Fredericks BM.  Scarce pose from the Bill Turner Collection.  John Sappington Marmaduke (March 14, 1833 – December 28, 1887) was an American politician and soldier. He was the 25th governor of Missouri from 1885 until his death in 1887. During the American Civil War, he was a senior officer of the Confederate States Army who commanded cavalry in the Trans-Mississippi Theater.On September 6, 1863, Marmaduke killed a Confederate brigadier general, Lucius M. Walker, in a duel. Confederate Major General Sterling Price ordered Marmaduke's arrest but suspended the order because of the impending U.S. advance on Little Rock, Arkansas. Marmaduke never faced a court martial for the duel.Early life and education