April 19, 1775 to March 17, 1776 action of militia and then the [[Dan's History Web/US 1/Topic Index/Continental Army]] preventing British troops from leaving [[Dan's History Web/US 1/Topic Index/Boston]] by land. In June 1775 British forces won the [[Battle of Bunker Hill]] at a high cost in casualties. The siege ended when [[George Washington|Washington]] installed artillery from [[Fort Ticonderoga]] on [[Dorchester Heights]], forcing [General Thomas Gage](https://en.wikipedia.org/wiki/Thomas_Gage) to abandon the city.