In 1774, Baldwin enlisted in a regiment, and commanded the Woburn militia at the
Battle of Lexington and Concord as a major. He is recorded as having described the events of April 19, 1775, as follows "We mustered as fast as possible. The Town turned out extraordinary, and proceeded toward Lexington." As a major at the time he continues "I rode along a little before the main body, and when I was nigh Jacob Reed's (at present Durenville) I heard a great firing; proceeded on, soon heard that the Regulars had fired upon Lexington people and killed a large number of them. We proceeded on as fast as possible and came to Lexington and saw about eight or ten dead and numbers wounded." He then, with the rest from Woburn, proceeded to Concord by way of Lincoln meeting house, ascended
a hill there, and rested and refreshed themselves a little. Then follows a particular account of the action and of his own experience. He had "several good shots," and proceeded on till coming between the meeting-house and Buckman's tavern at Lexington, with a prisoner before him, the cannon of the British began to play, the balls flying near him, and for safety he retreated back behind the meeting-house, when a ball came through near his head, and he further retreated to a meadow north of the house and lay there and heard the balls in the air and saw them strike the ground. Woburn sent to the field on that day, one hundred and eighty men. At the beginning of the war, he enlisted in the
26th Continental Regiment commanded by Colonel Samuel Gerrish. Here he rapidly advanced to be lieutenant-colonel, and upon Colonel Gerrish's retirement in August 1775, he was placed in command of the regiment, and was soon commissioned colonel. Until the end of 1775, Baldwin and his men remained near Boston, but in April 1776, he was ordered with his command to New York City. He took part in the
Battle of Pell's Point on October 18, 1776. On the night of December 25–26, in the face of a violent and extremely cold storm of snow and hail, General
Washington and his army
crossed the Delaware to the New Jersey side, and fought the
Battle of Trenton on the morning of December 26. Baldwin and his regiment participated in both the crossing and the fight. In 1777, Baldwin resigned from the army because of ill health. ==Political career==