the southern boundary of the District of Columbia is at Jones Point, and today the Woodrow Wilson Bridge is divided between three jurisdictions
Source: ESRI, ArcGIS Online
In 1632, Charles I issued a charter to the Calverts. When he gave them the new colony of Maryland, the king defined Virginia's new northern boundary as the southern shoreline (not the middle) of the Potomac River. The charter granted all of the Potomac River to Maryland, from the northern side to the "further Bank of the said River" on the Virginia side.
Creation of the District of Columbia in 1801 altered the Virginia-Maryland boundary Thomas Jefferson, Alexander Hamilton and James Madison had negotiated a deal in 1790 to put the Federal capital in Philadelphia for a decade, then relocate it to a new site on the Potomac River.
In the 1790 Residence Act, Congress gave President Washington authority to choose the specific location for a 100-square mile Federal district upstream of the Anacostia River. Maryland and Virginia passed legislation that permitted the Federal government to select up to 10 square miles of each state for the new District of Columbia.1
"Proclamation 1 - Defining the Boundaries of the District of Columbia," George Washington, January 24, 1791, posted online in The American Presidency Project, University of California, Santa Barbara, http://www.presidency.ucsb.edu/ws/index.php?pid=65589&st=virginia&st1=; "Residence Act," Library of Congress, https://www.loc.gov/rr/program/bib/ourdocs/Residence.html (last checked February 14, 2018)
Thomas Jefferson sketched the plan for the new capitol on the Potomac River
Source: Library of Congress, Residence Act (drawing by Thomas Jefferson)
Washington ignored the requirement to locate all of the capital upstream of the Anacostia River. Instead, he chose to locate the southern tip of the new District of Columbia at Jones Point.
That decision included Alexandria within the district, even though the town was downstream of the mouthof the Anacostia River. Congress quickly amended the Residence Act on March 3, 1791 to ratify George Washington's decision.
President Washington shaped the boundaries of the District so Virginia would contribute one-third of the land and Maryland would contribute the other two-thirds of the land. Both Maryland's port town of Georgetown and Virginia's port town of Alexandria were included in the new District.
George Washington, portrayed with his hand on a map of the District of Columbia
Source: Library of Congress, George Washington and his family by George Edward Perine
To define the exact boundaries of the 100-square mile district, Andrew Ellicott and his hired assistants (including Benjamin Banneker) surveyed four straight lines. Each was 10 miles long, running straight to the intersection with other boundary lines.
From Jones Point, the lines went 45° to the northeast and 45° to the northwest, then angled again after 10 miles to create a square. The survey lines defining the southeast and southwestern edges of the district cut straight across the Potomac River.
On a map oriented north-south, the new Federal district resembled a diamond with the southern tip at Jones Point. The surveyors erected stone markers one mile apart to document the boundary lines, with 14 stones used to mark the Virginia-District boundary.1
"Boundary Stones of the District of Columbia," http://www.boundarystones.org/ (last checked February 14, 2018)
the boundary between Virginia-DC, surveyed by Andrew Ellicott after the 1790 Residence Act, cut straight lines across the Potomac River and across topographic features
(note that north is to the upper left of the map, as indicated by the rosette)
Source: Library of Congress, Territory of Columbia
the portion of Virginia ceded to the District of Columbia was carved out of Fairfax County
Source: Library of Congress, Plan of the city of Washington (1800)
Maryland transferred jurisdiction over its portion of the new District of Columbia to the Federal government on December 19, 1791. In addition to the land, Maryland transferred all of the Potomac River inside the surveyed square. All of the Potomac River outside the District's surveyed boundary continued to be owned by Maryland. Virginia owned none of the Potomac River after 1632, so Virginia never transferred any part of the Potomac River to the District.
For a decade after the survey, Virginia transferred nothing to the District. That portion of the district Virginia committed to transfer, about one-third of the total, remained under Virginia jurisdiction. From the Federal government's perspective, it controlled land and water to the "further Bank of the said River" between 1791-1801, but did not control the land which Virginia planned to cede.
Cession of a slice of Maryland to the Federal government resulted in the first Virginia-District of Columbia boundary. It was on the southern edge of the Potomac River, stretching north from Jones Point towards Little Falls for roughly 12 miles.
The Virginia General Assembly agreed to cede its portion in 1789, but did not actually transfer the land until after the Federal government moved from Philadelphia to the District of Columbia. Virginia's legislators wanted the Federal government to establish some form of local government before ending Virginia's jurisdiction, so the territory would never be lawless. Even as late as 1801, the General Assembly passed laws that applied to the Virginia portion of the not-yet-established District.2
Phillips v. Payne, US Supreme Court, 1875, online in OpenJurist, http://openjurist.org/92/us/130 (last checked September 2, 2014)
Later in 1801, the Virginia General Assembly formally transferred jurisdiction of a slice of Fairfax County to the Federal government. That slice of Virginia transferred into the District, including the town of Alexandria, was given the name "Alexandria County."
The Virginia cession in 1801 altered the Virginia-District of Columbia boundary that had been created in 1791. Instead of running along the edge of the Potomac River, two straight lines surveyed by Ellicott now separated Fairfax County, Virginia, from the new Alexandria County, District of Columbia.
District of Columbia boundaries in 1835
Source: Library of Congress, District of Columbia
That Virginia-District of Columbia boundary lasted intact for 46 years. In 1846, the Federal government "retroceded" the Virginia portion of the District of Columbia. Jurisdiction of Alexandria County, including the town of Alexandria, was returned to Virginia. That shift became effective in 1847, once the Virginia General Assembly concurred with the decision by the US Congress and assumed jurisdiction.
With retrocession, Alexandria County became a new county in Virginia. The land ceded from Fairfax County in 1801 was not incorporated back into Fairfax County in 1847. As a result, Fairfax County was no longer the Virginia jurisdiction located adjacent to the District of Columbia.
Tn 1847, the new Virginia-District of Columbia boundary became the 12-mile stretch along the "further Bank" of the river again. The straight lines separating the two jurisdictions, based on Ellicott's survey, were replaced with a new boundary - the irregular shoreline of the south bank of the Potomac River.
Changes in Virginia jurisdictional boundaries altered the names on the Virginia side of its boundary with the District of Columbia, but not the location. After 1870, legislation based on the new state constitution defined Alexandria (incorporated in 1852 as a city) as an independent jurisdiction from Alexandria County. That created the City of Alexandria-DC boundary, and reduced the length of the County of Alexandria-DC boundary.
Annexation by the city in 1915, expanding its boundary and incorporating land that was within the county, extended the the City of Alexandria-DC boundary further and once again reduced the length of the County of Alexandria-DC boundary. In 1920, Alexandria County was renamed Arlington County, but the location of the county's boundary with the District of Columbia remained uchanged.
A final annexation by the City of Alexandria in 1929 incorporated a portion of Arlington County, extending the city's boundary to Four Mile Run. That annexation, together with the independence of cities and counties in Virginia, reduced the length of the Arlington-DC boundary and increased the length of the Alexandria-DC boundary.*
"A History of the Boundaries of Arlington County, Virginia," Office of the County Manager, Arlington, 1967, https://www.gutenberg.org/files/36902/36902-h/36902-h.htm (last checked February 14, 2018)
the City of Alexandria - District of Columbia border, from Jones Point to Four Mile Run, since 1929
Source: ESRI, ArcGIS Online
Alexandria annexed portions of Alexandria County in 1915 and Arlington County in 1929
Source: A History of the Boundaries of Arlington County, Virginia (Map IV)
Exactly where was the "shoreline" remained unclear until 1922. Virginia and Maryland agreed in an 1877 arbitration, the Black-Jenkins Award, that the low-water mark would define the boundary between those two states. The aritrators decided that Virginia had acquired prescriptive rights to the land between the high-water mark and the low-water mark, and Maryland accepted the low-water mark as part of the 1877 deal.
In 1921 in Marine Railway & Coal Co. vs US, the US Supreme Court stated "that the title of the United States embraces the whole river bed." In 1922 the Court of Appeals (District of Columbia Circuit) ruled in Herald v. United States that the Virginia-Maryland deal did not apply to the District of Columbia. The court ruled that the Virginia-District of Columbia boundary was the high-water mark on the Virginia shoreline. Virginia had prescriptive rights against Maryland, but not against the District of Columbia.
In 1931, the US Supreme Court adopted the same reasoning. It ruled in Smoot Sand & Gravel Corporation v. Washington Airport, Inc. that the high-water mark was the boundary. The boundary line between the District of Columbia and Virginia, at the time of Maryland's cession in 1791, was not affected by the 1877 Black-Jenkins Award in 1877 between Maryland and Virginia.2 Marine Railway & Coal Co. vs US, US Supreme Court, November 7, 1921, http://caselaw.findlaw.com/us-supreme-court/257/47.html; Herald v. United States, Court of Appeals (District of Columbia Circuit), 1922, https://archive.org/details/dc_circ_1922_3851_herald_v_us; Smoot Sand & Gravel Corporation v. Washington Airport, Inc., 283 U.S. 348, 1931, https://bulk.resource.org/courts.gov/c/US/283/283.US.348.678.html
The court decisions did not define the actual location of the high-water mark. Washington Airport was expanded by dumping fill on Potomac River mudflats in 1929. National Airport was created in 1941 by dredging the Potomac River and dumping fill on mudflats at Gravelly Point, downstream from Alexander Island. Both projecs opened the queston "where was the border?"
the boundary stones marking the District-Virginia and District-Maryland boundaries reveal the diamond pattern established by George Washington's decision to locate the southern tip at Jones Point
Source: ESRI, ArcGIS Online (with DC Boundary Stones layer)
Boundary Channel at Pentagon, with red line showing border between DC and Arlington County
1. 2. 3. 4. 5. 6.
George Washington (on horse) chose the site of the new national capital, Pierre Charles L'Enfant (showing sketch to Washington) prepared the initial city plan, and many unnamed slaves and free black laborers (such as the unidentified man holding the horse) built the structures such as the US Capitol
Source: Architect of the Capitol, Capitol Site Selection, 1791