"TheBattle of Bunker Hillwas fought on June 17, 1775. The colonists' militia groups had been camping around Boston since the outbreak of hostilities at Lexington and Concord on April 19. Now they were surrounding Boston in an effort to keep the British confined to the city.
Just before the 17th, the colonists learned the British were going to try to take possession of the hills surrounding the city. Boston itself sat on a piece of land that was mostly surrounded by water, with only a small neck of land connecting to the mainland. It was easy for the colonists to block that route.
Breed's HillandBunker Hilllay on another promontory north of Boston, along with the city of Charlestown. This was called Charlestown Peninsula and it was also connected to the mainland by a narrow neck of land. On the evening before the 17th, the colonists stealthily sent 1200 men to occupy Breed's Hill, which was closer to Boston. Bunker Hill lie behind it and was used for reserve troops."