John Harris ( USMC ) John Harris ( May 20 , 1793 – May 12 , 1864 ) was the sixth Commandant of the Marine Corps . He served in the Marine Corps for over 50 years , attaining the rank of colonel . Family . Harris was born in East Whiteland Township , Chester County , Pennsylvania , to an established local family that produced a number of military officers . His father , William Harris , was an officer in the American Revolutionary War . His older brother , Thomas , was a naval surgeon and became head of the navy ' s Bureau of Medicine and Surgery . His youngest brother , Stephen , married a granddaughter of Persifor Frazer ; Stephen ' s sons Stephen and Joseph both served in the Coast Survey before and during the American Civil War . Career . John Harris was commissioned a second lieutenant in the Marine Corps on 23 April 1814 . Two months later he was promoted to first lieutenant and , during the summer of that year , served with the forces that opposed the advance of the British on the city of Washington during the concluding days of the War of 1812 . The following year he was placed in command of the Marine Guard aboard USS " Macedonian " , which was one of the ships of the squadron of Commodore Stephen Decatur that sailed from New York in May 1815 on an expedition to punish the Barbary pirate s for their numerous depredations . Upon his return to the United States , 1st Lt Harris performed duty at Erie , Pennsylvania , and at Boston , Massachusetts . From the latter station he was assigned to duty aboard USS " Franklin " , which he joined in August 1821 . He was brevet ted captain on March 3 , 1825 , for distinguished conduct on that vessel . This was followed by tours of duty ashore at Boston and at sea , first in USS " Java " , then aboard the " Delaware " and " Philadelphia " . Promoted to the regular rank of captain on June 13 , 1830 , he was next stationed at Norfolk , Virginia . After that he rejoined the " Delaware " , from which ship he was detached in March 1836 . Three months later he joined the Philadelphia detachment of Marines at Fort Monroe , Virginia , for active duty with the Army in the field in the Florida Indian Wars . During the period of the Indian Wars in the South , he served with distinction in the Creek campaign in Alabama and in the war with the Seminole Indians in Florida . Colonel Commandant Archibald Henderson , who commanded the Marine Regiment during the troublesome times with the Indians , stated in a letter to the Secretary of the Navy that " Captain Harris while in Florida had command of Mounted Marines and did good service in that capacity . " Captain Harris was awarded brevet rank of Major ( United States ) on January 27 , 1837 , " for gallantry and good conduct in the war against Florida Indians , particularly in the affair of the Hatchee Lustee . " He returned to Washington in March 1837 as the bearer of a treaty which had been made by the commanding general with the Seminole chiefs . Promoted to major 6 October 1841 , he served until the Mexican - American War at Philadelphia , Washington , and Norfolk . In March 1848 , Major Harris was ordered to Mexico to cooperate on shore with the squadron off the Isthmus of Tehauntepec . He sailed from New York with a battalion of Marines , but upon their arrival at Veracruz , the armistice had been concluded . He was then ordered to garrison Alvarado with his battalion . Major Harris rejoined Headquarters in Washington , from Alvarado , in late summer of 1848 . His next assignments were as Commanding Officer of the Philadelphia and New York Marine Barracks . He was promoted to lieutenant colonel , December 10 , 1855 , and placed in command at Brooklyn , New York , where he remained until January 7 , 1859 , on which date he was appointed Colonel Commandant of the Marine Corps . At the age of 66 , he was the oldest officer to become Commandant of the Marine Corps . He likewise had seen more service than any officer receiving the appointment , having been a Marine for 45 years before becoming Commandant . Harris ' term as Commandant included a serious unfortunate incident shortly before the outbreak of the Civil War . At that time nearly half of his officers resigned to serve the Confederate States and he labored to reconstitute the weakened Corps . Also , during the early days of the Civil War , when contraband traffic began to flow from Maryland , Colonel Harris detailed an entire battalion of Marines to serve as United States Secret Service operators in the troubled area , with the result that the situation was well in hand within a brief period . Services rendered the Union by Marines under Harris were varied and many . Few , however , have been recorded as outstanding . This may be attributed to the fact that the Marine Corps of that period was composed of relatively few men in comparison with the strength of the Army or the regular Navy . The relatively minor role of the navy in the Civil War ( memorable almost exclusively for its land battles ) may be a factor as well . Harris died after a brief illness on May 12 , 1864 , while in office as Commandant of the Marine Corps . He had served as a marine officer for 50 years . He is buried in Oak Hill Cemetery in the Georgetown area of Washington , D . C .