https://en.m.wikipedia.org/wiki/Battles_of_Lexington_and_Concord
"The Battles of Lexington and Concord were the first military engagements of the American Revolutionary War.[9] They were fought on April 19, 1775, in Middlesex County, Province of Massachusetts Bay, within the towns of Lexington, Concord, Lincoln, Menotomy (present-day Arlington), and Cambridge, near Boston. The battles marked the outbreak of open armed conflict between the Kingdom of Great Britain and thirteen of its colonies on the mainland of British America.
In late 1774 the Suffolk Resolves were adopted to resist the enforcement of the alterations made to the Massachusetts colonial government by the British parliament following the Boston Tea Party. The colonial assembly responded by forming an illegal Patriot provisional government known as the Massachusetts Provincial Congress and calling for local militias to train for possible hostilities. The rebel government exercised effective control of the colony outside of British-controlled Boston. In response, the British government in February 1775 declared Massachusetts to be in a state of rebellion...."