On June 15, 1775, the Second Continental Congress unanimously approved John Adams’s nomination of Washington as commander of the Continental army. He served as leader of the colonial forces from the beginning of the war until the siege of Yorktown from Lord Charles Cornwallis in 1781. Washington often commanded troops who were besieged by superior armed forces and plagued with inadequate resources. He achieved a few victories, such as leading his troops across the Delaware River to surprise British forces in Trenton, New Jersey in 1776. But, he also suffered several notable defeats, including in New York and Pennsylvania. He and his troops suffered mightily during the winter at Valley Forge, Pennsylvania from 1777 to 1778.