March 17 is officially observed as Evacuation Day in Boston, even though St. Patrick’s Day falls on the same date. Here's the history of the pivotal day in Massachusetts (and American) history.

Evacuation Day is celebrated on March 17 and commemorates when, in 1776, George Washington and the Continental Army drove the British forces out of Boston, ending the 11-month siege that Britain and King George the III had those early Bostonians trapped in, according to the Secretary of State's website.