Born on April 4, 1823 in Mansfield, Ohio, the son of Gavin Mitchell. Of Scotch-Irish ancestry, Mitchell was married in January 1855 to Jennie St. John, by whom he was the father of Henry St. John and a child who died in infancy.
After studying law with John K. Miller in Mansfield, Ohio, Mitchell practiced law there from 1844 to 1846. He served as a Lieutenant in the Mexican War, and was wounded during the storming of Chapultepec. In 1855 he was elected Mayor of Mount Gilead, Ohio. In October of the following year, Mitchell went to Paris, Kansas and was elected to the Territorial Legislature, serving from 1857 to 1858. He subsequently acted as Treasurer of Kansas Territory from February 1859 to February 1861. At the beginning of the Civil War, he organized the Second Kansas Volunteer Infantry, serving with the rank of Colonel. Mitchell was cited for bravery at the Battle of Wilson Creek near Springfield, Missouri in August 1861; in April 1862 he was promoted to Brigadier General. In 1863 he arrested and threatened to shoot 350 of his men for mutiny. While he did not carry out the threat, that incident helped to establish his reputation for arrogance.
President Andrew Johnson nominated Mitchell as Governor of New Mexico Territory on December 14, 1865, and he took the oath of office on July 16, 1866. In November of 1866 Mitchell left the territory for almost four months, leaving Territorial Secretary William F.M. Amy as Acting Governor. When he returned he refused to recognize the laws and appointments made in his absence. This action initiated a long‑standing feud between the ill‑tempered governor and the Legislature. Although their pleas to President Johnson to have Mitchell removed fell on deaf ears, the Legislature did succeed in having Congress change that section of the Organic Act of New Mexico dealing with the governor’s power. The change limited the governor’s absolute veto power and allowed the Legislature to pass laws over a gubernatorial veto with a two‑thirds vote.
The territory had severe financial problems during Mitchell’s governorship and experienced deficit spending in 1868. Later in his term he declared war on the Gila Apache and the Navajo, an unpopular decision. Mitchell left office on August 16, 1869, but stayed in the territory to supervise the mining interests with which he had become involved during his governorship. He left the territory in March 1870, later moving to Kansas and Washington, D.C. Mitchell died on January 26, 1882 in Washington, D.C. and, following a Presbyterian service, was buried in the Congressional Cemetery.
Sources Used:
Washington Post, January 27 and 30, 1882.
Evening Star [Washington], January 28, 1882.
W.A. Mitchell, "Historic Linn," Collections of the Kansas State Historical Society, 16 (1923‑25), 632‑37.
Calvin Horn, New Mexico’s Troubled Years: The Story of the Early Territorial Governors (Albuquerque, 1963).
Howard R. Lamar, The Far Southwest, 1846‑1912: A Territorial History (New Haven, 1966). DAB.
Robert Byington Mitchell; Territorial Period; Governor of New Mexico