He was born in Roxbury, Massachusetts. After attending the Roxbury Latin School, he studied medicine at Harvard University, graduating in 1759. While practicing medicine and surgery in Boston, he joined the Freemasons and became involved in politics, associating with John Hancock, Samuel Adams and other radical leaders. He became Chairman of the Committee of Correspondence and was appointed a Grand Master of the Freemasons. He married Elizabeth Hooten, but she died in 1772, leaving him with three children. It is said the it was he who sent William Dawes and Paul Revere on their famous "Midnight Rides" to warn Lexington and Concord of the British raids on April 18 1775. He was appointed a Major General by the Massachusetts Provincial Congress, but fought at Bunker Hill as a volunteer in the front lines. He was killed during the battle, probably the first officer to die in the Revolutionary War. He drafted the Suffolk Resolves, which was endorsed by the Continental Congress, to advocate the forcible resistance to the British.