“Old Sam” Whittemore was about 80 when he encountered a British army of about 1,700. If a standard retirement age or the right to claim disability had existed in colonial America, Samuel Whittemore would probably not have felt these things were right for him. He was just one of the many minutemen who dropped his plow to take up his musket after the first shots at Lexington and Concord were fired, but he differed from most of his fellow embattled farmers in at least one important respect: he was not young. Nor was he middle-aged. Or even close to the standard retirement age. He was, in fact, the oldest combatant to serve in any American war. And despite sustaining terrible wounds from British soldiers that day, he survived to live for another 18 years. Among the many firsthand accounts that have come down to us from April 19, 1775, Samuel …