As evidence of his modesty, Washington said, "I do not consider myself equal to the command with which I am honored." First, Washington drove British troops out of Boston in 1776 during the Battles of Lexington and Concord. Thus, he lost many efforts in the battles to defend the New York colonies from the British forces. But on Christmas Day of that year he led his army through a heavy snowstorm, crossed the Delaware River into New Jersey, and defeated the British forces there. In 1778, the French agreed to an alliance with the Americans which can be considered a major turning point in the American Revolutionary War. The last major battle of the Revolutionary War was at Yorktown, Virginia, when Washington led his troops to victory with the help of French naval forces, thus they were able to defeat British General Charles Cornwallis and his forces in 1781 In 1783, Great Britain and the United States of America ended the Revolutionary War by signing the Treaty of Paris which declared them American.