Convinced that he could not suppress the rebellion in the Carolinas, Lord Cornwallis retreated to Virginia in 1781. Sir Henry Clinton, fearful of an American attack on his base in New York City, ordered Cornwallis to send part of his army to New York and to take up defensive positions in Virginia. Still confident that he could defeat the rebels, Cornwallis refused to send troops northward and began to build fortifications at Yorktown, along Chesapeake Bay.
Cornwallis's decision to take up positions at Yorktown, a peninsula formed by Virginia's York and James Rivers, proved to be a disastrous military mistake. A French fleet from the West Indies sailed to Chesapeake Bay, preventing Cornwallis's army from escaping by sea. A force of 7800 French peasants, 5700 Continental soldiers, and 3200 militia kept Cornwallis from retreating on land. Cornwallis held out for three weeks and then surrendered in October, while a British band played a tune called "The World Turned Upside Down." One quarter of the entire British army in America surrendered at Yorktown.
In a letter written precisely one month before Cornwallis's surrender, before the French and Americans had surrounded the British army, Edmund Pendleton assesses prospects for the future.
Very little important hath happen'd here, at least that has come to my knowledge, since the great event of the safe arrival of the Fleet & army of our good Ally [France].... It was supported that Earl Cornwallis would on their arrival, have endeavoured to effect an escape to the southward over James River; but whether the precautions taken by the Marquis [Lafayette] to prevent him, or his confidence in his own strength, or in being timely reinforced, influenced his stay, I know not, but so it is that he must now abide his fate at York Town, the French troops having landed at James Town & join'd the Marquis, so as to cut off his passage out of that neck so long as he is deprived of the dominion o'er the waters; and tho' he might cross his army over into Gloucester, where we have a body of militia, he could not that way expect to escape, since tho' they are not strong enough to oppose his army in the field, they might harass their march until a sufficient force could get above them & take them in that neck, but this I think they will not attempt, since by such a step they would immediately sacrifice all their vessels, which at present lie up York River above the town....
We expect here to have a busy autumn, supposing this is to become the seat of war since the Commander in Chief [George Washington] is to honour us with his presence; we are daily in expectation of his arrival by land, tho' we are told the troops come by water down the Bay.... We are told that the enemy give out that a superior fleet will soon drive off the French. Of such a fleet at New York, we have various accounts, some say they are 29 sail of the line, others 23 only...; but can they venture to draw all their fleet from New York & leave the French fleet behind them at Rhode Island? I think upon the whole that we must have this army, which will go a good way towards destroying their American forces & give the peace.