A census is the procedure of systematically acquiring and recording information about the members of a given population. The term is used in connection with national population and housing censuses; the United Nations defines the essential features of population and housing censuses as "individual enumeration, universality within a defined territory and defined periodicity", recommends that population censuses be taken at least every 10 years. United Nations recommendations cover census topics to be collected, official definitions and other useful information to co-ordinate international practice; the word is of Latin origin: during the Roman Republic, the census was a list that kept track of all adult males fit for military service. The modern census is essential to international comparisons of any kind of statistics, censuses collect data on many attributes of a population, not just how many people there are. Censuses began as the only method of collecting national demographic data, are now part of a larger system of different surveys.
Although population estimates remain an important function of a census, including the geographic distribution of the population, statistics can be produced about combinations of attributes e.g. education by age and sex in different regions. Current administrative data systems allow for other approaches to enumeration with the same level of detail but raise concerns about privacy and the possibility of biasing estimates. A census can be contrasted with sampling in which information is obtained only from a subset of a population. Modern census data are used for research, business marketing, planning, as a baseline for designing sample surveys by providing a sampling frame such as an address register. Census counts are necessary to adjust samples to be representative of a population by weighting them as is common in opinion polling. Stratification requires knowledge of the relative sizes of different population strata which can be derived from census enumerations. In some countries, the census provides the official counts used to apportion the number of elected representatives to regions.
In many cases, a chosen random sample can provide more accurate information than attempts to get a population census. A census is construed as the opposite of a sample as its intent is to count everyone in a population rather than a fraction. However, population censuses rely on a sampling frame to count the population; this is the only way to be sure that everyone has been included as otherwise those not responding would not be followed up on and individuals could be missed. The fundamental premise of a census is that the population is not known and a new estimate is to be made by the analysis of primary data; the use of a sampling frame is counterintuitive as it suggests that the population size is known. However, a census is used to collect attribute data on the individuals in the nation; this process of sampling marks the difference between historical census, a house to house process or the product of an imperial decree, the modern statistical project. The sampling frame used by census is always an address register.
Thus it is not known how many people there are in each household. Depending on the mode of enumeration, a form is sent to the householder, an enumerator calls, or administrative records for the dwelling are accessed; as a preliminary to the dispatch of forms, census workers will check any address problems on the ground. While it may seem straightforward to use the postal service file for this purpose, this can be out of date and some dwellings may contain a number of independent households. A particular problem is what are termed'communal establishments' which category includes student residences, religious orders, homes for the elderly, people in prisons etc; as these are not enumerated by a single householder, they are treated differently and visited by special teams of census workers to ensure they are classified appropriately. Individuals are counted within households and information is collected about the household structure and the housing. For this reason international documents refer to censuses of housing.
The census response is made by a household, indicating details of individuals resident there. An important aspect of census enumerations is determining which individuals can be counted from which cannot be counted. Broadly, three definitions can be used: de facto residence; this is important to consider individuals who have temporary addresses. Every person should be identified uniquely as resident in one place but where they happen to be on Census Day, their de facto residence, may not be the best place to count them. Where an individual uses services may be more useful and this is at their usual, or de jure, residence. An individual may be represented at a permanent address a family home for students or long term migrants, it is necessary to have a precise definition of residence to decide whether visitors to a country should be included in the population count. This is becoming more important as students travel abroad for education for a period of several years. Other groups causing problems of enumeration are new born babies, people away on holiday, people moving home around census day, people without a fixed address.
People having second homes because of working in another part of the country or retaining a holiday cottage are dif
Race and ethnicity in the United States Census
Race and ethnicity in the United States Census, defined by the federal Office of Management and Budget and the United States Census Bureau, are self-identification data items in which residents choose the race or races with which they most identify, indicate whether or not they are of Hispanic or Latino origin. The racial categories represent a social-political construct for the race or races that respondents consider themselves to be and, "generally reflect a social definition of race recognized in this country." OMB defines the concept of race as outlined for the US Census as not "scientific or anthropological" and takes into account "social and cultural characteristics as well as ancestry", using "appropriate scientific methodologies" that are not "primarily biological or genetic in reference." The race categories include both national-origin groups. Race and ethnicity are considered separate and distinct identities, with Hispanic or Latino origin asked as a separate question. Thus, in addition to their race or races, all respondents are categorized by membership in one of two ethnic categories, which are "Hispanic or Latino" and "Not Hispanic or Latino".
However, the practice of separating "race" and "ethnicity" as different categories has been criticized both by the American Anthropological Association and members of US Commission on Civil Rights. In 1997, OMB issued a Federal Register notice regarding revisions to the standards for the classification of federal data on race and ethnicity. OMB developed race and ethnic standards in order to provide "consistent data on race and ethnicity throughout the Federal Government; the development of the data standards stem in large measure from new responsibilities to enforce civil rights laws." Among the changes, OMB issued the instruction to "mark one or more races" after noting evidence of increasing numbers of interracial children and wanting to capture the diversity in a measurable way and having received requests by people who wanted to be able to acknowledge their or their children's full ancestry rather than identifying with only one group. Prior to this decision, the Census and other government data collections asked people to report only one race.
The OMB states, "many federal programs are put into effect based on the race data obtained from the decennial census. Race data are critical for the basic research behind many policy decisions. States require these data to meet legislative redistricting requirements; the data are needed to monitor compliance with the Voting Rights Act by local jurisdictions". "Data on ethnic groups are important for putting into effect a number of federal statutes. Data on Ethnic Groups are needed by local governments to run programs and meet legislative requirements." The 1790 United States Census was the first census in the history of the United States. The population of the United States was recorded as 3,929,214 as of Census Day, August 2, 1790, as mandated by Article I, Section 2 of the United States Constitution and applicable laws."The law required that every household be visited, that completed census schedules be posted in'two of the most public places within, there to remain for the inspection of all concerned...' and that'the aggregate amount of each description of persons' for every district be transmitted to the president."
This law along with U. S. marshals were responsible for governing the census. One third of the original census data has been lost or destroyed since documentation; the data was lost in 1790–1830 time period and included data from: Connecticut, Maryland, New Hampshire, New York, North Carolina, Rhode Island, South Carolina, Delaware, New Jersey, Virginia. Census data included the name of the head of the family and categorized inhabitants as follows: free white males at least 16 years of age, free white males under 16 years of age, free white females, all other free persons, slaves. Thomas Jefferson the Secretary of State, directed marshals to collect data from all thirteen states, from the Southwest Territory; the census was not conducted in Vermont until 1791, after that state's admission to the Union as the 14th state on March 4 of that year. There was some doubt surrounding the numbers, President George Washington and Thomas Jefferson maintained the population was undercounted; the potential reasons Washington and Jefferson may have thought this could be refusal to participate, poor public transportation and roads, spread out population, restraints of current technology.
No microdata from the 1790 population census is available, but aggregate data for small areas and their compatible cartographic boundary files, can be downloaded from the National Historical Geographic Information System. In 1800 and 1810, the age question regarding free white males was more detailed; the 1820
Interstate 24 is an Interstate Highway in the Midwestern and Southeastern United States. It runs diagonally from I-57, 10 miles south of Marion, Illinois, to Chattanooga, Tennessee, at I-75; as an even-numbered Interstate, it is signed as an east–west route, though the route follows a more southeast–northwest routing, passing through Nashville, Tennessee. Because the routing of I-24 is diagonal, the numbering is a bit unusual as it does not follow the Interstate Highway System numbering conventions. I-24 constitutes the majority of a high-traffic corridor between St. Louis and Atlanta; this corridor utilizes I-64 and I-57 northwest of I-24, I-75 southeast of I-24. I-24 begins near the community of Pulleys Mill; the highway heads southeast into rural Johnson County. It reaches an exit at Tunnel Hill Road, which serves Tunnel Hill; the highway continues south to its next exit at U. S. Route 45 north of Vienna, it reaches its next exit at Illinois Route 146 in eastern Vienna. I-24 heads southeast from Vienna into Massac County.
Its first exit in Massac County is at Big Bay Road, which serves the communities of Big Bay and New Columbia. I-24 continues southward; the highway passes west of Fort Massac State Park. It crosses the Interstate 24 Bridge over the Ohio River. After that, it continues into Kentucky. I-24 crosses into Kentucky on a bridge over the Ohio River, it passes to the west of Paducah and intersects US Routes 60, 45, 62. The freeway passes near Woodlawn-Oakdale and Reidland and connects with US 68; the welcome center in Paducah is Whitehaven. This is the only historic house in the country used as a rest area. East of this point, I-24 runs concurrently with I-69. Through this, it crosses the Tennessee and the Cumberland Rivers; the roadway travels along the north shore of the Cumberland River. I-69 splits off to the east just north of Mineral Mound State Park. I-24 continues away from the river, it runs through farmland for several miles. It passes south of Hopkinsville and interchanges with I-169. Near the Tennessee border, I-24 passes north of Fort Campbell.
Afterwards, it crosses into Tennessee. I-69 runs concurrently with I-24 for 17 miles from Calvert City to Eddyville. I-24 crosses into Tennessee traveling in a southeasterly and northwesterly direction in Clarksville, Montgomery County; the first interchange is with SR 48. I-24 has interchanges with US 79, SR 237, SR 76, crosses the Red River, it enters a long straight section, crossing into Robertson County, has interchanges with SR 256, SR 49 near Springfield, respectively. The route enters the rolling hilly terrain of the Nashville Basin, crosses into Cheatham County, where it has an interchange with SR 249. I-24 crosses into Davidson County, has an interchange with US 431; the interstate continues for several miles through rural woodlands before coming to an interchange with SR 45. Three miles I-24 crosses the Nashville Urban Boundary, widens to six lanes, has an interchange with SR 155, the northern beltway around Nashville. Less than a mile I-24 joins a concurrency with Interstate 65, where the combined routes carry ten through lanes, travel due south.
About two miles I-65 splits off, I-24 enters downtown Nashville, where it has interchanges with US 41, US 431, US 31E, as well as several city streets. I-24 crosses the Cumberland River, joins in a concurrency with Interstate 40, travelling southeast with eight through lanes, two miles I-40 splits off eastwardly, heading toward Knoxville. Located at this interchange is an interchange with US 41, less than a mile is an interchange with the eastern terminus of Interstate 440, accessible from I-40 nearby. About a mile is once again an interchange with SR 155/Briley Parkway near the Nashville International Airport, I-24 continues southeast, bisecting a major residential area. Here I-24 carries eight through lanes, beginning at the next exit, SR 255, the left lanes operate as HOV lanes during rush hour. I-24 continues southeast through the growing suburbs of Nashville, crosses into Rutherford County near the city of LaVergne, where there are three exits. Beginning at this point, I-24 is straight and flat for most of its distance through Middle Tennessee.
The straightest stretch of highway in Tennessee is located on I-24 between Lavergne and eastern Murfreesboro, where the route is straight for about fifteen miles, although the median widens and narrows. Four miles is an interchange with SR 102, which connects to Smyrna and the Nissan Motor Manufacturing Plant. Another four miles is an interchange with Interstate 840, the outer southern beltway around Nashville, I-24 enters Murfreesboro, the largest suburb of Nashville. In Murfreesboro, I-24 has interchanges with SR 96, SR 99, US 231 and at the final Murfreesboro exit, the HOV lane designation ends, I-24 narrows to six lanes and four lanes a short distance later. Three miles is an interchange with the Joe B. Jackson Parkway, which serves as an outer beltway around southeast Murfreesboro. I-24 enters a more rural area, at exit 97 has an interchange with SR 64, which connects to Shelbyville. I-24 curves to the south the east enters Bedford County, Coffee County. At exit 105 is an inter
Interstate 57 is an Interstate Highway in Missouri and Illinois that parallels the old Illinois Central rail line for much of its route. It goes from Sikeston, Missouri, at Interstate 55 to Chicago, Illinois, at Interstate 94. I-57 serves as a shortcut route for travelers headed between the south and Chicago, bypassing St. Louis, Missouri. Between the junction of I-55 and I-57 in Sikeston and the junction of I-55 and I-90/94 in Chicago, I-55 travels for 436 miles, while the combination of I-57 and I-94 is only 396 miles long between the same two points. In fact, both the control cities on the overhead signs, as well as destination mileage signs, reference Memphis along southbound I-57 as far north as its northern origin at I-94 in Chicago. At its southern end, Chicago is the control city listed for I-57 on signs on northbound I-55 south of Sikeston, Missouri though I-55 goes to Chicago; as of 2015, I-57 are any planned for the near future. At a length of just over 386 miles, it is the second longest two-digit Interstate Highway without an auxiliary route, behind I-49.
I-57 has one business loop in Missouri. In the state of Missouri, Interstate 57 runs northbound from Sikeston to the Cairo I-57 Bridge over the Mississippi River south of Cairo, Illinois. After ending southbound at Interstate 55, the highway continues as U. S. Route 60, which meets U. S. Route 67 at Poplar Bluff and from there U. S. Route 67 goes south to Arkansas. From the start of I-57 northbound, the US 60 concurrency goes about 12 miles. In the state of Illinois, Interstate 57 runs from the bridge over the Mississippi River north to Chicago. I-57 is the longest Interstate Highway in Illinois, its route follows the earlier route of US 51 in southernmost Illinois before taking a northeastward diagonal to Illinois 37, which remains intact as a town-to-town through route, past its interchange with Interstate 24 near Pulleys Mill and a short duplex with Interstate 64 near Mount Vernon north to Effingham, where it has a short concurrence with Interstate 70. It follows US 45 bypassing cities of Champaign and Urbana, heads north to Onarga whereafter it follows the duplex path of US 45 and old US 54 to Kankakee.
At Kankakee it heads northward parallel to the now decommissioned route of old US 54 into the Chicago area, meeting Interstate 80 in Hazel Crest, Interstate 294 in Blue Island, feeding Interstate 94 on Chicago's South Side. Although I-57 serves as a long-distance bypass of St. Louis, the section between Mount Vernon and Pulleys Mill contains the most direct Interstate route between St. Louis and cities to the southeast of St. Louis, it serves as the northwestern terminus of Interstate 24 that leads southeastward to those cities and as the eastern terminus of Interstate 72 near Champaign. The route is an easy way for Chicagoans to reach Shawnee National Forest in the southern tip of the state, it serves as a major artery for college students in the state, running near Shawnee Community College in Ullin, the main campus of Southern Illinois University in Carbondale, John A. Logan College in Carterville, Morthland College in West Frankfort, Rend Lake College in Ina, Lake Land College in Mattoon, Eastern Illinois University in Charleston, Parkland College in Champaign, University of Illinois at Urbana–Champaign in Urbana–Champaign, Kankakee Community College in Kankakee, Olivet Nazarene University in Bourbonnais, Governors State University in University Park.
Interstate 57 and Interstate 294 did not have an intersection for a long time, though phase one opened on October 25, 2014. It was one of only a few examples where Interstates cross but didn't have interchanges with each other. Vehicles were directed to use Interstate 80 to access Interstate 294 instead, though U. S. Route 6 was another option. I-57 remains the only Chicago expressway that does not have a used name, its Chicago-area portion was known as the Dan Ryan Expressway–West Leg. I-57 was named the Ken Gray Expressway in southern Illinois after former U. S. Congressman Ken Gray for his work on getting the route planned through southern Illinois. A 20-mile segment from Wentworth to Sauk Trail has been designated the Tuskegee Airmen Memorial Trail but this is not intended as a navigational name; the portion between the Route 121/US 45 exit and the Watson–Mason exit was completed and opened prior to July 1965, linking I-57 to I-70, running in tandem with I-70 for several miles, with access to Indianapolis to the east, St. Louis to the west.
A 21.5-mile section of I-57 in Jefferson County from Bonnie to Route 161 opened on December 9, 1969. The final section of I-57 in Illinois opened in December 1971 at Paxton; the portion of Interstate 43 from Milwaukee to Green Bay was numbered as Interstate 57. The number was changed due to the existence of I-57 in Illinois. I-57 was widened to six lanes in Effingham from 2011 until 2016. I-57 is slated to be extended west along US 60 to Poplar Bluff and south along the US 67 corridor to North Little Rock, ending at I-40. In April 2016, a provision designating US 67 from North Little Rock to Walnut Ridge, Arkansas, as "Future I-57" was added into the federal fiscal year 2017 Transportati
Population density is a measurement of population per unit area or unit volume. It is applied to living organisms, most of the time to humans, it is a key geographical term. In simple terms population density refers to the number of people living in an area per kilometer square. Population density is population divided by total land water volume, as appropriate. Low densities may lead to further reduced fertility; this is called the Allee effect after the scientist. Examples of the causes in low population densities include: Increased problems with locating sexual mates Increased inbreeding For humans, population density is the number of people per unit of area quoted per square kilometer or square mile; this may be calculated for a county, country, another territory or the entire world. The world's population is around 7,500,000,000 and Earth's total area is 510,000,000 square kilometers. Therefore, the worldwide human population density is around 7,500,000,000 ÷ 510,000,000 = 14.7 per km2. If only the Earth's land area of 150,000,000 km2 is taken into account human population density is 50 per km2.
This includes all continental and island land area, including Antarctica. If Antarctica is excluded population density rises to over 55 people per km2. However, over half of the Earth's land mass consists of areas inhospitable to human habitation, such as deserts and high mountains, population tends to cluster around seaports and fresh-water sources. Thus, this number by itself does not give any helpful measurement of human population density. Several of the most densely populated territories in the world are city-states and dependencies; these territories have a small area and a high urbanization level, with an economically specialized city population drawing on rural resources outside the area, illustrating the difference between high population density and overpopulation The potential to maintain the agricultural aspects of deserts is limited as there is not enough precipitation to support a sustainable land. The population in these areas are low. Therefore, cities in the Middle East, such as Dubai, have been increasing in population and infrastructure growth at a fast pace.
Cities with high population densities are, by some, considered to be overpopulated, though this will depend on factors like quality of housing and infrastructure and access to resources. Most of the most densely populated cities are in Southeast Asia, though Cairo and Lagos in Africa fall into this category. City population and area are, however dependent on the definition of "urban area" used: densities are invariably higher for the central city area than when suburban settlements and the intervening rural areas are included, as in the areas of agglomeration or metropolitan area, the latter sometimes including neighboring cities. For instance, Milwaukee has a greater population density when just the inner city is measured, the surrounding suburbs excluded. In comparison, based on a world population of seven billion, the world's inhabitants, as a loose crowd taking up ten square feet per person, would occupy a space a little larger than Delaware's land area; the Gaza Strip has a population density of 5,046 pop/km.
Although arithmetic density is the most common way of measuring population density, several other methods have been developed to provide a more accurate measure of population density over a specific area. Arithmetic density: The total number of people / area of land Physiological density: The total population / area of arable land Agricultural density: The total rural population / area of arable land Residential density: The number of people living in an urban area / area of residential land Urban density: The number of people inhabiting an urban area / total area of urban land Ecological optimum: The density of population that can be supported by the natural resources Demography Human geography Idealized population Optimum population Population genetics Population health Population momentum Population pyramid Rural transport problem Small population size Distance sampling List of population concern organizations List of countries by population density List of cities by population density List of city districts by population density List of English districts by population density List of European cities proper by population density List of United States cities by population density List of islands by population density List of U.
S. states by population density List of Australian suburbs by population density Selected Current and Historic City, Ward & Neighborhood Density Duncan Smith / UCL Centre for Advanced Spatial Analysis. "World Population Density". Exploratory map shows data from the Global Human Settlement Layer produced by the European Commission JRC and the CIESIN Columbia University
Illinois is a state in the Midwestern and Great Lakes region of the United States. It has the fifth largest gross domestic product, the sixth largest population, the 25th largest land area of all U. S. states. Illinois is noted as a microcosm of the entire United States. With Chicago in northeastern Illinois, small industrial cities and immense agricultural productivity in the north and center of the state, natural resources such as coal and petroleum in the south, Illinois has a diverse economic base, is a major transportation hub. Chicagoland, Chicago's metropolitan area, encompasses over 65% of the state's population; the Port of Chicago connects the state to international ports via two main routes: from the Great Lakes, via the Saint Lawrence Seaway, to the Atlantic Ocean and from the Great Lakes to the Mississippi River, via the Illinois Waterway to the Illinois River. The Mississippi River, the Ohio River, the Wabash River form parts of the boundaries of Illinois. For decades, Chicago's O'Hare International Airport has been ranked as one of the world's busiest airports.
Illinois has long had a reputation as a bellwether both in social and cultural terms and, through the 1980s, in politics. The capital of Illinois is Springfield, located in the central part of the state. Although today's Illinois' largest population center is in its northeast, the state's European population grew first in the west as the French settled the vast Mississippi of the Illinois Country of New France. Following the American Revolutionary War, American settlers began arriving from Kentucky in the 1780s via the Ohio River, the population grew from south to north. In 1818, Illinois achieved statehood. Following increased commercial activity in the Great Lakes after the construction of the Erie Canal, Chicago was founded in the 1830s on the banks of the Chicago River at one of the few natural harbors on the southern section of Lake Michigan. John Deere's invention of the self-scouring steel plow turned Illinois's rich prairie into some of the world's most productive and valuable farmland, attracting immigrant farmers from Germany and Sweden.
The Illinois and Michigan Canal made transportation between the Great Lakes and the Mississippi River valley faster and cheaper, new railroads carried immigrants to new homes in the country's west and shipped commodity crops to the nation's east. The state became a transportation hub for the nation. By 1900, the growth of industrial jobs in the northern cities and coal mining in the central and southern areas attracted immigrants from Eastern and Southern Europe. Illinois was an important manufacturing center during both world wars; the Great Migration from the South established a large community of African Americans in the state, including Chicago, who founded the city's famous jazz and blues cultures. Chicago, the center of the Chicago Metropolitan Area, is now recognized as a global alpha-level city. Three U. S. presidents have been elected while living in Illinois: Abraham Lincoln, Ulysses S. Grant, Barack Obama. Additionally, Ronald Reagan, whose political career was based in California, was born and raised in the state.
Today, Illinois honors Lincoln with its official state slogan Land of Lincoln, displayed on its license plates since 1954. The state is the site of the Abraham Lincoln Presidential Library and Museum in Springfield and the future home of the Barack Obama Presidential Center in Chicago. "Illinois" is the modern spelling for the early French Catholic missionaries and explorers' name for the Illinois Native Americans, a name, spelled in many different ways in the early records. American scholars thought the name "Illinois" meant "man" or "men" in the Miami-Illinois language, with the original iliniwek transformed via French into Illinois; this etymology is not supported by the Illinois language, as the word for "man" is ireniwa, plural of "man" is ireniwaki. The name Illiniwek has been said to mean "tribe of superior men", a false etymology; the name "Illinois" derives from the Miami-Illinois verb irenwe·wa - "he speaks the regular way". This was taken into the Ojibwe language in the Ottawa dialect, modified into ilinwe·.
The French borrowed these forms, changing the /we/ ending to spell it as -ois, a transliteration for its pronunciation in French of that time. The current spelling form, began to appear in the early 1670s, when French colonists had settled in the western area; the Illinois's name for themselves, as attested in all three of the French missionary-period dictionaries of Illinois, was Inoka, of unknown meaning and unrelated to the other terms. American Indians of successive cultures lived along the waterways of the Illinois area for thousands of years before the arrival of Europeans; the Koster Site demonstrates 7,000 years of continuous habitation. Cahokia, the largest regional chiefdom and urban center of the Pre-Columbian Mississippian culture, was located near present-day Collinsville, Illinois, they built an urban complex of more than 100 platform and burial mounds, a 50-acre plaza larger than 35 football fields, a woodhenge of sacred cedar, all in a planned design expressing the culture's cosmology.
Monks Mound, the center of the site, is the largest Pre-Columbian structure north of the Valley of Mexico. It is 100 feet high, 951 feet long, 836 feet wide, covers 13.8 acres. It contains about 814,000 cubic yards of earth, it was topped by a structure thought to have measured about 105 feet in length and 48 feet in width, covered an area 5,000 square feet, been as much as 50 feet high, making its peak 150 feet above the level of the pl
U.S. Route 45
U. S. Route 45 is a major north–south United States highway and a border-to-border route, from Lake Superior to the Gulf of Mexico. A sign at the highway's northern terminus notes the total distance as 1,300 miles. US 45 is notable for incorporating, in its maiden alignment, the first paved road in the South, a 49-mile segment in Lee County, Mississippi. Let to contract in July 1914, the concrete highway opened on November 15, 1915; as of 2006, the highway's northern terminus is in Ontonagon, Michigan, at the corner of Ontonagon and River Streets, a few blocks from Lake Superior. M-64 terminated there as well until its rerouting in October 2006 to use the newly built Ontonagon River Bridge, its southern terminus is in Mobile, Alabama, at an intersection with U. S. Route 98. US 45 is concurrent with unsigned SR 17 between Mobile and Vinegar Bend, just north of Deer Park, in Washington County, Alabama. From Vinegar Bend to the Mississippi state line, US 45 is concurrent with unsigned SR 57. U. S. Highway 45 is part of a designated hurricane evacuation route in Mississippi.
It is four-laned from its point of entry from Alabama, at the town of State Line, to the Tennessee line just north of Corinth, along the way serving the towns of Waynesboro, Meridian and Tupelo. At Brooksville, U. S. 45 splits away from U. S. 45 Alternate and serves the towns of Columbus and Aberdeen before rejoining U. S. 45 Alternate south of Tupelo. The alternate roadway provides a more direct and four-laned route between Meridian and Tupelo, bypassing Columbus to the west and, more Starkville to the east. Major junctions of U. S. 45 in Mississippi include U. S. Route 84 at Waynesboro, Interstate 20/59 at Meridian, U. S. Route 82 at Columbus, Interstate 22/U. S. Route 78 at Tupelo and U. S. Route 72 at Corinth; each of these junctions is an interchange and, with the exception of Waynesboro, each is part of a freeway segment. The Mississippi section of U. S. 45 is defined at Mississippi Code Annotated § 65-3-3. From the Mississippi state line U. S. 45 extends north past Selmer and Jackson to Three Way, just north of Jackson.
At Three Way, the highway splits into U. S. 45E and U. S. 45W. From Three Way to the northeast, U. S. 45E extends past Milan Martin and is concurrent with unsigned State Route 43 for most of the route's length past except for short segments at South Fulton and Martin, where it is cosigned with State Route 216 and State Route 215 respectively. From Three Way to the northwest, U. S. 45W extends past Humboldt and is concurrent with unsigned State Route 5 to Union City and with U. S. 51 to the junction with U. S. 45E less than a quarter mile south of the Kentucky state line. Mainline U. S. 45, concurrent with U. S. 51, continues north into Kentucky. U. S. 45 enters Kentucky at Fulton northeast past Mayfield heads directly north into Paducah as a four-lane highway. In Paducah, U. S. 45 serves as a major artery, intersecting with Interstate 24 at exit 7, intersecting US 60 and 62. U. S. 45 leaves Kentucky from Paducah's northern border across the two-lane, metal-grate Brookport Bridge to Brookport, Illinois across the Ohio River.
In the state of Illinois, U. S. 45 runs from a bridge across the Ohio River from Paducah, through Shawnee National Forest and north to the Wisconsin border east of Antioch, Illinois. With a length of 428.99 miles in Illinois, U. S. 45 is the longest numbered route in Illinois. In its progress north from the Ohio River U. S. 45 first joins Interstate 24 as far as Vienna heads northeast through Harrisburg and north through Fairfield, Effingham, Champaign, Urbana and Kankakee straight north through the western suburbs of Chicago in Will County, Cook County and Lake County to the Wisconsin border. U. S. 45 enters the state in southeast Wisconsin. It runs concurrent with Interstate 894 and U. S. Route 41 through the west side of metro Milwaukee to form a major artery through the metropolitan area, it runs north to Fond du Lac. The highway routes near the western shore of Lake Winnebago through Wisconsin. U. S. 45 travels north through Wittenberg and Eagle River, as well as the state and national forests, until it leaves the state at Land O' Lakes and enters Michigan.
US 45 enters Michigan south of Watersmeet. From there, the highway crosses the Western Upper Peninsula through the Ottawa National Forest running north to Ontonagon. US 45 ends just south of Lake Superior in downtown Ontonagon; the terminus was not changed in 2006 despite realignment of M-38 and M-64 from the terminus to a crossing 0.7 miles south. Until March 1935, US 45's northern terminus was in the Illinois area. Prior to the construction of the Interstate Highway system, US 45 was one of the main routes south out of Chicago toward New Orleans, Louisiana. Much of the traffic left US 45 at Effingham, continuing on through Cairo, Illinois along Illinois Route 37. Southern segmentAlabama US 98 in Mobile I‑65 in Prichard Mississippi US 84 in Waynesboro I‑20 / I‑59 in Meridian US 11 / US 80 in Meridian US 82 west of Columbus; the highways travel concurrently to Columbus. US 278 north-northwest of New Wren; the highways travel concurrently to the Verona–Tupelo city line. I‑22 / US 78 in Tupelo US 72 in Corinth Tennessee US 64 in Selmer.
The highways travel concurrently through the city. I‑40 / US 412 in Jackson US 45E / US 45W in Three Way US 79 in Milan US 79 in Humboldt Northern segmentTennessee US 45E / US 45W / US 51 in South Fulton. US 45 / US 51 travel concurrently to Fulton, Kentucky. Kentucky Future I‑69 north of Mayfield I‑24 in Paducah US 62 in Paducah; the highways travel concurrently through the city. US 60 / US 62 in Paducah. US 45/US 60 travels concurrently throu