Rosecrans, William S. (1819–1898), Civil War general, businessman, and politician.Ohio‐born and largely self‐educated, Rosecrans graduated from West Point in 1842. Resigning his commission after twelve uneventful years, he pursued a variety of unsuccessful business ventures. Rejoining the army in 1861 as a brigadier general in the Civil War, he conducted the critical operations that ejected Confederate forces from western Virginia. In 1862 he moved to the western theater, leading part of the Union army that seized Corinth, Mississippi. Thereafter, as a district commander, he held his own in the indecisive battles of Iuka and Corinth.

Promoted to major general, Rosecrans assumed command of the Army of the Cumberland in late October 1862. Charged with regaining middle and eastern Tennessee for the Union, he advanced from Nashville in December and precipitated the Battle of Stones River. After two days of intense fighting, he successfully held the field, thereby winning the Union's only military triumph at the end of 1862.

Six months later, Rosecrans resumed his advance toward Chattanooga, Tennessee. Clearing middle Tennessee in the masterful Tullahoma campaign, he next lunged across the Tennessee River into Georgia, driving Confederate forces from Chattanooga. Incautiously continuing his advance until confronted by a reinforced Army of Tennessee, he was attacked on Chickamauga Creek—the Battle of Chickamauga—in late September. Nearing exhaustion, he issued a faulty order that collapsed his line and forced him from the field while much of his army still resisted. Relieved of command in October, he was given the Department of Missouri in 1864 but did not distinguish himself during a Confederate raid.

Postwar, Rosecrans served variously as minister to Mexico, register of the Treasury, congressman, and California rancher. Brilliant but erratic, touted before Chickamauga as a potential general in chief or presidential candidate, Rosecrans saw his military career essentially ended by a single error in judgment on 20 September 1863.
[See also Civil War: Military and Diplomatic Course.]

Bibliography

William M. Lamers , The Edge of Glory: A Biography of General William S. Rosecrans, 1961.
Peter Cozzens , This Terrible Sound: The Battle of Chickamauga, 1992.

William Glenn Robertson