September 28, 1781

Siege of Yorktown

The Franco-American army invests Yorktown

Washington opened the siege before his artillery was ready — two American howitzers and numerous gun carriages were stranded aboard a sloop stuck on a sandbar.

28 September 1781: the march from Williamsburg

At about five in the morning on 28 September 1781, the combined American and French army marched from Williamsburg toward the British positions at Yorktown. Washington divided the advance into columns — American Continental and French troops on the left, Virginia militia on the right — and the two national contingents later separated onto different roads.

Around noon the column heads reached their assigned ground. French troops drove in British pickets on the allied left; British cavalry retired before the right.

A mile from the works, sleeping on their arms

By nightfall the allies held temporary positions along Beaverdam Creek, approximately a mile from the principal British posts, and the land encirclement had begun. Washington ordered the entire army, officers and enlisted men alike, to lie on their arms in the open.

The allied force numbered roughly 17,600 American and French soldiers against about 8,300 British, German auxiliary and Loyalist troops in Yorktown.

Why the hurry, and what came next

French control of the Chesapeake had closed Cornwallis's sea route, but de Grasse was expected to remain only temporarily — so Washington pressed forward before all his artillery and transport had arrived, short even of horses and wagons to move field guns and entrenching tools from Williamsburg.

This began the investment and siege operations, though the first formal parallel was not dug until 6 October and the bombardment began on 9 October. During the night of 29 September Cornwallis abandoned most of his outer works, which the allies occupied on the 30th.

Sources

Researched 23 Aug 2026 6 sources 3 audit passes

How this was checked

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What the sources leave uncertain

Published strength totals vary depending on whether returns count militia, marines, sailors, detachments at Gloucester, and troops present versus effective. The NPS estimate of approximately 17,600 allies and 8,300 defenders is used here.
September 28 marks the beginning of the investment and siege operations. The first formal siege parallel was not dug until October 6, and the artillery bombardment began October 9.