Index American Revolution: http://www.historyplace.com/unitedstates/revolution/index.html
An Unlikely Victory: timeline of Revolution: http://www.historyplace.com/unitedstates/revolution/revwar-77.htm#letters
October 17, 1781 - As Yorktown is about to be taken, the British send out a flag of truce. Gen. Washington and Gen. Cornwallis then work out terms of surrender.
Letters exchanged between Cornwallis and Washington regarding the surrender: 10/17/1781 http://www.historyplace.com/unitedstates/revolution/letters.htm