April morning by Howard Fast.

A short novel about the first days of the American Revolution as experienced by a 15-year-old boy. Adam Cooper has a little brother who annoys him and a father who fails to appreciate him. Adam dares to sign the muster roll of the Lexington militia. When you read this novel about April 19, 1775, you will see the British redcoats marching in a solid column through your town. Your hands will be sweating and you will shake a little as you grip your musket because never have you shot with the aim of killing a man. But you will shoot, and shoot again and again while your shoulder aches from your musket's kick and the tight, disciplined red column bleeds and wavers and breaks and you begin to shout at the top of your lungs because you are there, at the birth of freedom -- you're a veteran of the Battle of Lexington, and you've helped whip the King's best soldiers.