约克镇围城战役（或称约克镇战役）爆发于1781年，乔治·华盛顿将军率领的美军和罗尚博伯爵带领的法军联手围攻困守约克镇的英军（由查尔斯·康沃利斯将军指挥），并最终获得了决定性的胜利。在美国独立战争中，通常认为这场战役是最后一场陆上大型战斗。在康沃利斯的军队投降之后（这是英军主力第二次投降，第一次是柏戈因在萨拉托加战役后的投降），英国政府决定进行谈判并结束这场战争。

1780年，5,500名法军在罗德岛登陆，以协助他们的美国盟友进攻被英国所占领的纽约市。两军于1781年在纽约市北方会师。法军指挥官——罗尚博伯爵告诉美军指挥官——乔治·华盛顿进攻纽约市的行动是几乎不可能成功的，又由于德·葛拉瑟伯爵才刚于10月时率领舰队从加勒比海赶来，因此围攻约克镇将会使葛拉瑟伯爵率领的法国舰队，更容易从南方协助进攻。于是，他们决定进攻驻防在约克镇的康沃利斯以及其麾下仅约9,000人的军队。9月初，德·葛拉瑟在切萨皮克湾海战击败了赶来援救康沃利斯的英国舰队。由于德·葛拉瑟获得了此场胜利，于是康沃利斯从海上脱逃的希望消失了。华盛顿下令法国将军拉法叶侯爵在他赶到之前务必将康沃利斯围困在约克镇，而拉法叶也确实做到了。至9月底，联军在陆地上已经彻底封锁了康沃利斯。

The Siege of Yorktown, also known as the Battle of Yorktown, the Surrender at Yorktown or the German Battle, ending on October 19, 1781, at Yorktown, Virginia, was a decisive victory by a combined force of American Continental Army troops led by General George Washington and French Army troops led by the Comte de Rochambeau over a British Army commanded by British lord and Lieutenant General Charles Cornwallis. The culmination of the Yorktown campaign, the siege proved to be the last major land battle of the American Revolutionary War in the North American theater, as the surrender by Cornwallis, and the capture of both him and his army, prompted the British government to negotiate an end to the conflict. The battle boosted faltering American morale and revived French enthusiasm for the war, as well as undermining popular support for the conflict in Great Britain.