In the fall of 1776, a British naval force left Canada and entered Lake Champlain in an effort to divide and conquer the rebelling thirteen colonies. Off Valcour Island, a fleet of gunboats under Benedict Arnold met it on 11 October, beginning an intensive three-day engagement fought across more than 30 miles of the lake. By the end of the third day, the British had gained control of the strategic waterway, but the advancing season forced them to return to Canada for the winter. Although the little American navy on Champlain was wiped out, the delay it secured had a profound impact on the outcome of the Revolutionary War and on winning American independence.