The battle that occurred just before Yorktown and set the stage for the siege was the Battle of Virginia Capes.

The Battle of Virginia Capes, fought in September 1781, was a crucial naval confrontation that took place just before the Siege of Yorktown. In this battle, the French fleet, led by Admiral de Grasse, engaged the British naval forces. The French victory ensured their dominance over the Chesapeake Bay, blocking British reinforcements from reaching General Cornwallis. This strategic edge enabled American and French troops to effectively lay siege to Cornwallis’s forces at Yorktown. The triumph at the Virginia Capes was instrumental in paving the way for the eventual surrender of British troops, playing a significant role in the quest for American independence.