Following the British evacuation of Boston, Massachusetts, on March 17, 1776, Washington led the Continental Army (the Main Army) to New York City. He left a Continental garrison at Boston, under Major General Artemas Ward, in case the British should return. In the summer of 1776 it became clear to Washington that the main British effort would be directed against New York City and northern New York, and he reached the conclusion that the Continental regiments at Boston were more urgently needed elsewhere. He therefore ordered them to reinforce either his own army or the Northern Army under Major General Philip Schuyler. The Eastern Department became a secondary theater until the Battle of Rhode Island in 1778.