On the night of March 4–5, 1776, George Washington executed one of the most audacious maneuvers of the entire war: the overnight fortification of Dorchester Heights. Dorchester Heights was a series of elevated hills on a peninsula to the south of Boston, overlooking both the city and its harbor. Military leaders on both sides understood the significance of this ground. Whoever controlled it could place artillery in a position to rain fire down on the town and the British ships anchored below.