1820: Col (Brevet BGen) Archibald Henderson

At the age of 37, Colonel Archibald Henderson became the fifth Commandant of the Marine Corps. He held this position for more than 39 years, outlasting nine presidents. 
 
Henderson is remembered for his personal commitment to his Marines and his straightforwardness. In 1836, Henderson went in person to fight alongside his Marines in the Florida Indian War, leaving a simple note on his door: "Have gone to Florida to fight Indians. Will be back when war is over."