As the host of WGBH Journal, Bill Cavness, put it 36 years ago, “Today is not just St. Patrick’s Day. In Boston, schools, banks and other public offices are closed because it is Evacuation Day. Evacuation Day commemorates the final departure of the British from Boston in 1776 during the American Revolutionary War.”
Have a listen to this clip found in the American Archive for Public Broadcasting and learn about why the British troops left Boston and how Evacuation Day became a holiday.
Written and edited by Bill Nehring, American Archive intern at WGBH.
blog.americanarchive.org 
I wanted to pin this to my “All Things Irish” board on Pinterest, but, alas, there is no way to pin it. Great post. thanks for the history.