On April 19, 1775, when was a around 80 years old, Whittemore was in his fields when he spotted an approaching group of British soldiers. Instead of hiding, Whittemore loaded his musket and ambushed the soldiers killing one. Then he then drew his dueling pistols, killed a second grenadier and mortally wounded a third. By the time he had fired his third shot, a British detachment had reached his position so Whittemore drew his sword and fought.
He was subsequently shot in the face, bayoneted numerous times, and left for dead in a pool of blood. He was found by colonial forces, trying to load his musket to resume the fight. He was taken to a doctor, who perceived no hope for his survival. However, Whittemore recovered and lived another 18 years and he died peacefully at the age of 98. Samuel is a hero.