Map of the Way out of Boston

Charles Swift at the City Record and Boston News-Letter has observed Evacuation Day by posting a map of Revolutionary Boston and some surrounding towns—many of which were eventually absorbed by the city. I believe this map was derived from one created by Henry Pelham in 1777, which showed all the fortifications inside and outside the town.

Note Dorchester Heights, item #4. Large cannons brought by Fort Ticonderoga by Henry Knox provided the decisive threat that prompted the British military to leave on 17 March 1776. Pelham and Knox were classmates at the South Latin School in the late 1750s; both eventually dropped out.