This department existed in two separate periods. This department was created on October 16, 1862. It was geographically defined by Cairo, Illinois; Fort Henry and Fort Donelson in Tennessee; northern Mississippi; and Kentucky and Tennessee west of the Tennessee River. Fort Henry and Fort Donelson were transferred into the Department of the Cumberland on January 25, 1863. Fort Heiman was transferred to the Department of the Cumberland in 1863. The department became a part of the Military Division of the Mississippi on October 16, 1863, along with the Departments of the Cumberland and the Ohio. Cairo, Illinois briefly became part of the Northern Department on January 12, 1864, but returned to the Department on February 8, 1864. On August 7, 1864, Kentucky west of the Tennessee River became part of the Department of the Ohio and Cairo, Illinois became part of the Northern Department. On November 8, 1864, the department also included Army of Tennessee troops that occupied the Tennessee River and parts of Alabama and Mississippi. This department was disbanded on November 28, 1864. Commander(s): Ulysses S. Grant, William T. Sherman, James B. McPherson, John A. Logan, Oliver O. Howard, and John A. Logan. The second Department of the Tennessee was created on June 27, 1865. It was geographically defined by the state of Tennessee and was assigned to the Military Division of Tennessee. This department was disbanded on June 5, 1866 and merged into the Department of the Cumberland. Commander(s): George Stoneman.