Dorchester is remembered in American history for an action in the American Revolutionary War known as the Fortification of Dorchester Heights. After the battles of Lexington and Concord, Revolutionary sentiment within New England reached a new high, and thousands of militiamen from the Northern colonies converged on Boston, pushing the British back within what were then relatively narrow city limits. In June 1775 British soldiers under General William Howe attacked and seized Bunker Hill, but in the process sustained many losses. Following this encounter, the Continental Congress in Philadelphia gave George Washington the title of commander-in-chief and sent him to oversee the Siege of Boston.