Following the skirmishes at Lexington and Concord on April 19, 1775, colonial militia had surrounded Boston, pinning the British in. Lt. General Thomas Gage that knew he was surrounded on land, so he had to control Dorchester Heights and Charlestown to keep the harbor open to British ships. The Americans were able to occupy the Charlestown peninsula before the British. On June 15, ramparts were ordered to be built on Bunker Hill. By the morning of June 17, extensive fortifications had been built on Breed's Hill by the colonials.
Lt. General Gage then sent British ships to bombard the hill, while Maj. General William Howe prepared to sail across the bay and retake the position that afternoon. At three o'clock in the afternoon, the British finally began an assault on the hill. The Americans repulsed them twice, but due to twindling ammunition, they were forced to abandon the position during the third British assault. Though the British technically won, it came at a high cost and Lt. General Gage resigned his command.
View the following pages for more detailed information on the Battle of Bunker Hill: