[3] However, in 1775, he established a local Stafford County militia company and soon abandoned his studies and took up arms against the British government during the Revolutionary War.

William and his elder brother, Henry, reputedly drew straws to see who would get to join the Continental Army and who would stay home and manage the family plantations.

At the Battle of Trenton, under command of Nathanael Greene and after a night of scouting the countryside with Monroe to prevent detection, Washington led a successful assault into the town.

On November 19, 1779, his unit was transferred to the war's Southern theater, and marched to join the army of Major General Benjamin Lincoln in Charleston, South Carolina.

On March 10, 1780, Washington's regiment joined forces with the remnants of the 1st Continental Light Dragoons at Bacon's Bridge, South Carolina, to reconnoiter and screen against the advancing British.

On March 26, his first encounter with the British Legion, under command of Lieutenant Colonel Banastre Tarleton, resulted in a minor victory near Rantowle's Bridge on the Stono River in South Carolina.

Two notable successes were the capture of Rugeley's Mill near Camden on December 4, 1780; Washington with 60 troops bluffed 112 Loyalists into surrendering a strongly fortified homestead without firing a shot by use of a "Quaker Gun", mounting a felled tree trunk on wagon axles to resemble a cannon; and the defeat of a Tory partisan unit at Hammond's Old Store in the Little River District on December 27, 1780; Washington routed 250 Georgia Loyalists, killing or wounding 150 and capturing the rest.

These successes led to Tarleton being ordered by Lord Cornwallis to chase down Morgan's "flying corps", leading to the Battle of Cowpens on January 17, 1781.

Morgan's battle plans called for Washington's group, 80 Continental dragoons and 45 mounted Georgia infantry, to serve as a defensive and offensive unit as the situation required.

[5] For his valor at Cowpens, Washington received a silver medal awarded by the Continental Congress executed under the direction of Thomas Jefferson.

After the Battle of Cowpens, Washington's dragoons assisted the retreat of General Nathanael Greene to Dan River in Virginia by rearguard actions against forces commanded by Lord Cornwallis.

Midway through the battle, Greene ordered Washington to charge a portion of the British line positioned in a blackjack thicket along Eutaw Creek.

The British commander in the South, Lord Cornwallis, would later comment that "there could be no more formidable antagonist in a charge, at the head of his cavalry, than Colonel William Washington.

"[6] On April 21, 1782, Washington married Jane Riley Elliott of Sandy Hill plantation in Charleston County, South Carolina.

After the war, the married couple settled on Sandy Hill plantation, which was 28 miles upriver from the port at Charleston, South Carolina[7] and which Jane Elliott owned before their marriage.

He showed skill, bravery, and daring on the battlefield, inspiring victory and confidence in the war of American Independence from the British Crown.