Monday, April 15, is Patriots Day, a state holiday marking the anniversary of the Battle of Lexington and Concord that began the American Revolution. The day has been celebrated on the third Monday in April since 1969.

It was on the morning of April 19, 1775, that Paul Revere and other riders began the alert across and beyond Massachusetts Colony that troops were planning to advance from Boston to the towns of Lexington and Concord. They were to seize a cache of gunpowder and arms and capture revolutionaries Sam Adams and John Hancock.

(Local legend claims that Israel Bissell, later of Hinsdale, rode all the way to Philadelphia, but most historians dismiss it.)

Previous attempts to capture munitions depots from the increasingly belligerent colonials had failed, so Lt. Col. Francis Smith led some 700 British regulars on what was supposed to be a secret mission against the nearby towns. Colonial spies were aware of the expedition and some local militia was mustered on the Lexington green the night before.

Whether it was a colonial or soldier who fired "the shot heard round the world" on Lexington green is unknown. However, word spread quickly that shots had been fired at Lexington and more colonials headed to Concord. The army took the town but came under fire at North Bridge and beat an ignomious retreat to Boston.

Adams and Hancock evaded capture and much of the arms had been scattered to surrounding towns long before the army arrived. As reports of the events spread throughout the colonies, supplies and reinforcements, including George Washington, began arriving to relieve Boston. A year later, the British army would leave on March 17; the event is commemorated in Suffolk County as Evacuation Day.

Patriots Day is also known as "Marathon Monday" because the Boston Marathon, the world's oldest annual marathon, has traditionally been run on that day. This year will be the 117th race. The Red Sox will be at Fenway playing the Tampa Bay Rays.

Income taxes: Patriots Day often meant extra time for New England tax-filers because returns were processed at the Andover facility, which closed for the holiday. The IRS discontinued that practice because of the increasing number of e-filers. No holiday relief this year: Income tax forms are due before midnight on Monday, April 15.

Closed:
Municipal, county and state offices
Public schools; it marks the first day of spring vacation
Public colleges, including MCLA and BCC
Public libraries

Open:
BRTA operating on regular schedule
Restaurants, bars, convenience stores, supermarkets, retail stores, liquor stores
Banks may open if they wish; all markets are open
Federal offices open: mail is delivered