Robert Byington Mitchell Robert Byington Mitchell ( April 4 , 1823January 26 , 1882 ) was a brigadier general in the Union Army during the American Civil War and the Governor of the New Mexico Territory from 1866 to 1869 . Early life and career . Mitchell was born on April 4 , 1823 , in Mansfield , Ohio . For some odd reason , it was recorded that he graduated from both Kenyon College and Washington College , although neither school has a record of his attendance . He studied law in Mount Vernon , Ohio . After completing his studies , he practiced law in Mansfield . He served in the Mexican War as a second lieutenant in the 2nd Ohio Volunteers . He was elected mayor of Mount Gilead , Ohio , in 1855 . Next year , he moved to Linn County , Kansas Territory . He served in the territorial legislature , as a delegate to the Leavenworth Convention , from 1857 to 1858 . He served as treasurer of the Kansas Territory from 1859 to 1861 . He was a delegate to the 1860 Democratic National Convention in Charleston , South Carolina . Civil War service . After the start of the Civil War , Mitchell served as the Adjutant General of Kansas from May 2 , 1861 to June 20 , 1861 . He later led the 2nd Kansas Infantry . He was badly wounded at the Battle of Wilson ' s Creek on August 10 , 1861 . He was shot from his horse while leading his regiment . After recovery , U . S . President Abraham Lincoln appointed him as a brigadier general to rank from April 8 , 1862 , and he was given command of a mixed brigade at Fort Riley . He commanded the 9th Division in Charles C . Gilbert ' s III Corps at the Battle of Perryville . He was then sent to Nashville , Tennessee , where he remained for several months . During the Chickamauga campaign , Mitchell served as George H . Thomas ' s Chief of Cavalry for the Army of the Cumberland . Just before the Third Battle of Chattanooga , he was ordered to Washington , D . C . , for court - martial duty . According to some sources , this was due to severe wounds which incapacitated him from field duty but this is contradicted in the " Official Records " by Mitchell ' s own correspondence . Whether incapacitated or not , he would not see active campaigning again , and for the remainder of the Civil War , he commanded the District of Nebraska , then the District of North Kansas , and finally the District of Kansas . He saw service in Colorado Territory in January , 1865 , following the Indian raid on Julesburg , Colorado on the Overland Trail , but did not succeed in locating the Indian camp on the Republican River until after they had departed . Governor of New Mexico Territory . Mitchell was honorably mustered out of the army on January 15 , 1866 . On the same day , the United States Senate confirmed his nomination as the Governor of the New Mexico Territory . He took the oath of office on June 6 , 1866 . He never appeared to take his duties as governor seriously . He often was absent from the territorial capital Sante Fe , without explanation , forcing the legislature to forward bills it had passed to Washington , D . C . , for approval of the United States Congress . He resigned as governor in 1869 . Later life . After leaving the office , Mitchell returned to Kansas . He was unsuccessful in his bid to represent Kansas in the U . S . Congress in 1872 . He then moved to Washington , D . C . , where he died on January 26 , 1882 . He was buried with full military honors in Section 2 , Grave 1023 , of Arlington National Cemetery in Arlington , Virginia .