On June 13, 1775, the Americans learned that the British generals were planning to send troops out from the city to occupy the unoccupied hills around the city. In response to this, 1,200 colonial troops under the command of William Prescott stealthily occupied Bunker Hill and Breed's Hill, constructed an earthen redoubt on Breed's Hill, and built lightly fortified lines across most of the Charlestown Peninsula.