Samuel Whittemore was born in Charlestown, Massachusetts, in 1696. He served as a private in Col. Jeremiah Moulton's Third Massachusetts Regiment, where he fought in King George's War (1744–48). He was involved in the capture of the French stronghold, the Fortress of Louisbourg in 1745. Recent sources suggest he fought in the French and Indian War(1754–63) at the age of 64, once again assisting in the capture of the Fortress of Louisbourg, and later in a military expedition against Chief Pontiac in 1763.

Whittemore was in his fields when he spotted an approaching British relief brigade under Earl Percy, sent to assist the retreat. Whittemore loaded his musket and ambushed the British Grenadiers of the 47th Regiment of Foot from behind a nearby stone wall, killing one soldier. He then drew his dueling pistols, killed a second grenadier and mortally wounded a third. By the time Whittemore had fired his third shot, a British detachment had reached his position; Whittemore drew his sword and attacked. 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 Dr. Cotton Tufts of Medford, who perceived no hope for his survival. However, Whittemore recovered and lived another 18 years until dying of natural causes at the age of 96.