forts were built to block foreign ships from sailing up the James and Elizabeth rivers, and when cannon were finally powerful enough forts were built at Cape Charles and Cape Henry to control passage into the Chesapeake Bay
Map Source: US Fish and Wildlife Service, Wetlands Mapper
The Chesapeake Bay was a highway, even for the Native Americans. Powhatan's control extended to the Eastern Shore, though his canoes were far less maneuverable than the European ships. Powhatan had no technology capable of blocking the arrival of European ships, or the capacity to sink ships of the invading Tassautessus (strangers). He relied instead on diplomacy, while his successors attempted to use surprise attacks to expel the invaders.
Until the advent of Inter-Continental Ballistic Missiles (ICBM's) in the 1950's, the greatest external military threat to Virginia was a military force attacking via the Chesapeake Bay. The range of land-based cannon (shore batteries) was inadequate to block the entrance to the James River until Fort Calhoun was constructed on the Rip-Raps shoal between Hampton and Norfolk in the 1840-50's.
The Virginians knew the Atlantic Ocean was not a perfect barrier (just as England worried about invasion across the English Channel by the Spanish in 1588, the Dutch in 1677, the French in 1779, and the Germans in 1941). The earliest English settlers in 1607 chose to sail past the excellent harbors on the Elizabeth River (Norfolk and Portsmouth), as well as the future port at Newport News. They went 30 miles upstream to Jamestown, to reduce the potential of a surprise attack by the Spanish, French, or Dutch.
For 350 years after Jamestown, any nation at war has threatened the American ships and cargoes at Hampton Roads. In colonial times, the ships were far more valuable than the public buildings at the colonial capital - and today, the same may be true regarding the Atlantic Fleet based at Norfolk.
In addition, the plantations along the shorelines in Tidewater had to be wary of pirate attacks until the 1800's. Ships flew clearly-identifiable flags to announce their allegiances, but there was always the potential that a sail spotted downstream really meant the arrival of a pirate masquerading as a merchant from England or the West Indies - or a rebel.
During Bacon's Rebellion in 1675-76, Governor Berkeley fled Jamestown to safety on the Eastern Shore. Bacon sent a ship to Northampton Copunty under Captain Carver and Squire Bland to arrest the governor. While Carver negotiated on land, perhaps for an excessive amount of time as Berkeley kept refilling the glass of wine, Berkeley's forces secretly rowed out to the ship and captured it before Bland could react. With control of the seas, Berkeley could safely return to the Peninsula and challenge Bacon - who died before there was any climactic battle.
Chesapeake Bay - British attack routes in 1780-81
Old Point Comfort, at tip of the Peninsula, has been fortified since 1609. Fort Monroe, completed in 1834, was the prison for Confederate President Jefferson Davis in 1865-67. Fort Monroe was decommissioned in 2011 after the Base Realignment and Closure (BRAC) process, and was declared a National Monument in 2012
Source: US Geological Survey, Hampton 7.5x7.5 topographic quad (2011)
Though the Chesapeake Bay was a highway, the expanse of water was also a protective barrier. Pirates or countries with a navy found the time required to cross the bay would provide the Virginians with a key advantage. The military observation posts located at Hampton and Cape Charles/Cape Henry provided advance warning of ships entering the bay, so Virginia's militia could be assembled before an attacking force sailed across the bay to a target.
The Jamestown settlers built Fort Algernourne in 1609, near the town of Kecoughtan (on the end of the Peninsula, where Fort Monroe is now located). Moving some starving settlers away from Jamestown in 1609 reduced the demand on the fort's food supplies, and may have reduced transmission of density-dependent disease. The fort also provided an early warning system of Spanish, Dutch, and pirate ships. The Agernourne Oak on the parade ground at Fort Monroe germinated around 1540, so that live oak tree would have provided shade for the colonists who built the first fort.1
In 1667, the "Point Comfort Fort" was useless in protecting the tobacco fleet in the James River from capture by two Dutch warships. Maintaining the fort's walls required labor, reducing the time spent in the fields growing tobacco amd earning an income. In addition, guns at the fort were not powerful enough to hit enemy ships sailing in the channel. In theory the tobacco fleet could have sailed near the fort and received protection, but in practice the fort was nothing but a drain on the valuable time of the Virginia colonists.
Fort George was built on the same site in 1727. It was destroyed by the 1749 hurricane that first created Willoughby Spit. Hampton Roads offers several sheltered locations for a harbor, but a storm surge of 10-15 feet still can rearrange the channels and spits as well as sink ships/destroy buildings.
Since the 1748 Treaty of Aix-la-Chappelle had ended the War of Austrian Succession (also known as King George's War) between France and England, Fort George was not rebuilt. During the Seven Years War (also known as the French and Indian War), Virginia focused on defending its western borders rather than building maginally-useful forts at the mouth of the Chesapeake Bay. The end of the Cold War in the 1990's, which led to the closure of modern Fort Monroe at the tip of the Peninsula, was not the first time Virginia faced demobilization of military bases after international tensions were relaxed.
Until World War II, forts at Hampton Roads were unable to block enemy ships from sailing into the Chesapeake Bay or up the James River because cannon were not powerful enough to hit a ship from in the channel. In Hampton Roads, an enemy ship could sail next to the southern shoreline of the James River, out of range from the artillery on the Peninsula. The colonial gunpowder lacked the "oomph" to push cannonballs across the river, so enemy ships could navigate upstream while out of range of forts on either shoreline. Even if the gunpowder had been more powerful, the iron used for cannon barrels could not have contained and channeled stronger explosions.
The solution was to manufacture a new island in the middle of Hampton Roads. Starting in 1819, the Americans sought to fortify the natural reef called Rip-Raps shoal about halfway between Hampton and Norfolk. Mounds of granite from quarries near Baltimore were piled onto the Rip-Raps, but the heavy stones sank into the soft sediments.
Rip-Raps got its name from the rippling of the water, as the Chesapeake Bay encountered a shalow a shoal off the Peninsula. After seven years of reinforcing the shoal with heavy stone, the army began construction of Fort Calhoun on the new man-made island. Robert E. Lee's first assignment after graduating from West Point in 1829 was to serve as an engineer on that project.
The island kept sinking, and the project continued for 30 more years after Lee moved on. If you're cynical about government waste, the conversion of the Rip-Raps into a military fort will reinforce your opinion.
Fort Calhoun was not finished when Virginia seceded from the Union in 1861, but it and Fort Monroe were too strong to be captured by the Confederates. The Confederates burned Hampton in 1861 to provide a clear field of fire against the Yankee-controlled fort - but naturally they blamed the destruction on the Union side.
Fort Calhoun was renamed Fort Wool in 1862, shifting the honor from a South Carolinian who advocated secession to the Union General, John Wool, who finally captured Norfolk on May 9, 1862. Three months after the Monitor and the Virginia had dueled to a draw on March 9, Union general George McClellan used Fort Monroe as his staging base to support his army on the Peninsula and finally marched to Williamsburg - but General McClellan ignored the threat of the Confederates in Norfolk, across the James River.
Abraham Lincoln is given credit by some for directing the Union Army and Navy to cooperate and join forces to eliminate the Confederates from the south bank of the James. In 1862, Yankee cannon at Fort Wool had sufficient range to reach the Confederate fortifications across Hampton Roads at Sewell's Point (now the location of the Norfolk Naval Base, home bases of nuclear-powered aircraft carriers). The Union Navy ferried 6,000 troops to Ocean View east of Willoughby Spit, Norfolk surrendered quickly, and the Confederates burned the Virginia because the James River upstream of Newport News was too shallow for the ship weighted down with iron.
By capturing Portsmouth and Norfolk, the Yankees forced the Confederates to abandon their last efforts to use the Virginia to control the sea lanes at Hampton Roads. However, the Confederates fortified Drewry's Bluff upstream, and blocked the Union navy from sailing up the James River and supporting the army during the Seven Days battle, when Richmond was at great risk of being captured.
Virginia has always needed some sort of a navy to defend itself from sea-borne attack. Weapons capable of actually blocking entrance into the Chesapeake Bay were not available until World War II. Ships were needed to engage other ships on the water - and the failure to have a defensive naval force until the Spanish-American War left Virginia open to invasion more than once.
Virginia and the United States declined to invest in building and maintaining a standing navy to guard the bay for the first 300 years of European settlement. In the colonial era and during the Confederacy, Virginia assembled the best sailing fleet it could on short notice only after a threat was clearly recognized - and always too late to provide much protection. Just as Powhatan was unable to block the English from sailing up the James River in 1607, the Virginians were unable to block the British in early 1781 or the Yankees in 1862.
It's surprising to realize that the defense of the mouth of the Bay and Hampton Roads has been so essential to blocking enemy military advances. In the Revolutionary War, when the American rebels had no warships in the Bay, the British were able to raid up the Elizabeth, Nansemond, Appomattox, James, and Potomac rivers with ease.
In May, 1779, Sir George Collier led 28 ships with 1,800 men under General Edward Mathew and surprised the Virginians in Hampton Roads. Fort Nelson, guarding the Gosport shipyard in Portsmouth, was quickly captured because only 100 men were stationed there. The fort was very well constructed, and with the British attacking by land there was no problem with the range of the Virginia weapons. However, the British forces outnumbered the Virginians 20-1, and the Virginia commander wisely retreated.
The Collier-Mathew raid made Virginia's legislators realize that the Revolutionary War would be fought in their state, as well as in the north between Philadelphia and Boston. The raid destroyed extensive supplies in Norfolk, Portsmouth, and Suffolk, as well as warships under construction, Merchant ships loaded with tobacco for France ended up as prize ships, and the profits went to British officers rather than helping the American side. Including the ships seized in the upper Chesapeake Bay, 137 vessels were captured by the British at the cost of just two men being wounded. By the time the Virginia militia had been assembled, the British had left... though British warships continued to patrol the Chesapeake Bay in 1779, with no resistance by the Americans.1
Another British invasion in 1780 showed Virginia was better prepared to defend itself. General Alexander Leslie brought only a half-dozen or so ships - but 2,200 men - when he landed at Portsmouth on October 21 and Newport News/Hampton on October 23, 1780. The intent was to intercept Virginia supplies and divert American troops away from the British campaign under Lord Cornwallis, as they marched north from recently-captured Charleston, SC.
However, the Virginians mobilized while minimizing the impact on their support for the Southern armies. Most of the Virginia Line had been captured in the disastrous defeat at Charleston, but the rebellious Americans were still resisting Conwallis' northern advance. Virginia sent its reinforcements and supplies south, rather than to George Washington's army keeping the British trapped in New York City.
The British forces captured the battlefield at Camden, Kings Mountain, Cowpens, and Guilford Courthouse, but those Pyrrhic skirmishes were costing the British irreplaceable soldiers. Remember, the British were already hiring mercenaries, Hessian soldiers from Germany. Recruiting and shipping replacement troops across the Atlantic was as challenging as getting American soldiers to Vietnam 35 years ago.
General Leslie was deterred from sailing up the James by reports of large groups of Virginia militia and strong fortifications on the riverbanks. The Virginians freed up the guards responsible for 2,800 British prisoners in Charlottesville, shipping them further inland to Maryland. The Barracks Road Shopping Center just north of the University of Virginia basketball stadium was named after the quarters built by those prisoners, who had been captured at the Battle of Saratoga in 1777 and marched to Virginia for safekeeping.2
However, the arrival of General Benedict Arnold with nearly 1,500 troops and over 20 ships on December 30 showed Virginia's military defenses were inadequate. Arnold reached Jamestown before Thomas Jefferson called out the militia. The British marched quickly from William Byrd's plantation wharf at Westover to Richmond, where they destroyed the Westham foundry that produced cannon for the Americans. (It was about 1 mile downstream from the current Huguenot Bridge in West End Richmond, on the north bank.) The Virginians did manage to move most supplies to the south side of the James River, and the militia blocked the British from capturing Petersburg.
Arnold retreated to Portsmouth, but after being reinforced with 2,000 more troops in March the British (now under General William Phillips) could raid throughout Tidewater with impunity. On one raid, they sailed past Mount Vernon before seizing merchant ships and tobacco from Alexandria. The caretaker (Lund Washington, cousin of George Washington) provided them supplies in exchange for protecting the mansion - to George Washington's great embarrassment.
General Phillips captured Petersburg in April, 1781. Colonial Heights gets its name from the artillery fired from that location by General Lafayette. He could harass the British, but the Continental Army keeping the British trapped in New York City could not spare enough troops to interfere with Arnold's plans.
By the time General Cornwallis reached the Dan River at the Virginia-North Carolina border, Virginia was clearly unable to protect itself. The state knew it needed assistance from the other colonies. To encourage the Congress to contribute more troops to protect Virginia, the state decided to cede its claims to western lands north of the Ohio and grant whast became the "Northwest Territory" to the national government.
The Americans had raced ahead of Cornwallis from the defeat at Charleston until he reached the south bank near South Boston. They moved all the boats to the north bank to block him from crossing, and in some cases the Americans were just barely across the Dan River when the British scouts first arrived on the other shore.
In April, 1781, the British general chose to abandon the pursuit of the American forces and march to the sea, leaving Piedmont Virginia largely unscathed by the Revolutionary War. He moved first to Wilmington, NC, and then marched overland to Petersburg in May, 1781. Cornwallis crossed the James River to the wharf at Westover, then marched north to Hanover Court House and up to the Rapidan River. (Lafayette fled to the north bank, crossing at Ely's Ford.) There were no military resources or tobacco worth capturing or destroying at Fredericksburg, so that town was spared a visit by the British.
Charlottesville was not so lucky. The General Assembly had abandoned Richmond and fled inland, and the British considered the rebel leaders to be an attractive target. Col. Banastre Tarleton (the villain in the movie The Patriot) led a fast raid to Charlottesville. However, while Tarleton's Legion stopped briefly at a tavern in Louisa County, Jack Jouett started a dramatic nightime ride to warn the General Assembly. He had to avoid the main roads where the British were arresting everyone. Reportedly, Jouett's face was scarred for life from the branches that he hit in the dark, on the way to Charlottesville. He got there just in time. Governor Thomas Jefferson, at the end of his term in that office, fled across Carter's Mountain as the British reached Monticello. The General Assembly fled across the Blue Ridge to Staunton.
Colonel John Simcoe led a simultaneous British raid on the north bank of the James River to Point of Fork, at the mouth of the Rivanna River. There he captured a large number of Virginia supplies. General Baron von Steuben managed to escape with most of the Continental Army supplies to the south bank of the river, but the Virginia state officials were less sucessful. Steuben described his maneuvers as succcessful, since he had fulfilled his mission - but that obviously ignored the overall impact of the military losses due to the American inability to defend any fixed location against the British forces in 1781.
The amazing defeat of Cornwallis at Yorktown can be explained best by the amazing unwillingness of the British commanders to work as members of a team. The British army depended upon re-supply from the sea. The Americans had minimal naval assets, and the British had defeated the French several times in previous naval engagements.
The French were unwilling to gamble along with George Washington in an attack on New York, because the British fleet and soldiers on the ground were too powerful. They were willing to strip all of their ships from the West Indies and create an extraordinarily large fleet for a brief moment, however. The American and French troops stationed outside of New York marched south to the Chesapeake, where the French provided transportation to the Peninsula. The Americans marched their artillery by land to Conwallis's encampment at Yorktown, and between the two countries they outnumbered the British in troops and artillery.
What mattered, however, was the fact that the British fleet was defeated by French fleet on September 5, 1781. The French sailed out of Chesapeake Bay, surprising the British with the number of "ships of the line" assembled in one force. The Battle of the Capes was a draw, basically, with each navy punishing the other but not gaining domination over the other. The French retained control of the Chesapeake Bay and the British fleet returned to New York for repairs. As a result, for the first time since the Revolutionary War started, Cornwalis was trapped and unable to get new supplies or troops.
Cornwallis played it safe and waited for help, while Washington and the French allies gambled and won at Yorktown. Had Cornwallis showed more energy, he could have broken through the French or American lines before they established siege trenches and trapped him in Yorktown. In particular, he could have crossed the York River and marched north past Gloucester as the Americans/French were marching south from New York. However, he waited too long, assuming his commander in New York would deliver on his promises and prevent Cornwallis from being trapped. When Cornwallis finally tried a breakout, a storm prevented the British ships from evacuating Yorktown and on October 19, 1781, he surrendered.
(A year later, in the Battle of the Saintes, the French fleet was destroyed by the English.)