In April 1861 a Virginia state convention voted to secede and join the Confederacy. However, there was much opposition to this action from the western counties of the state, which were economically tied closer to western Pennsylvania and Ohio than to eastern Virginia. Following the secession vote in Richmond, John Carlile, a Unionist leader from northwest Virginia, led a meeting at Clarksburg which called for a convention to meet at Wheeling the next month for determining what steps "the people of Northwest Virginia should take in the present emergency."
To organize Union forces in the area, George B. McClellan was appointed commander of the Department of the Ohio, covering Ohio, Indiana, Illinois, western Pennsylvania, and western Virginia. He gathered several regiments raised in Ohio, Indiana, and western Virginia and moved into Virginia in early May, moving along the Baltimore and Ohio Railroad and the Kanawha River. The Confederates appointed several commanders to organize troops in western Virginia: Colonel George A. Porterfield in northwestern Virginia, and Brigadier Generals John B. Floyd and Henry A. Wise in the Kanawha Valley. This divided command structure prevented the Confederates from coordinating their response to the Union invasion; in addition, General Robert E. Lee, commander of the Virginia militia forces, underestimated the strength of Unionist support in western Virginia.
The Union army would occupy the western region of Virginia for the rest of the war, despite several raids by the Confederates into the area. West Virginia would later be split from the Department of the Ohio and be formed into a new Department of Western Virginia. The Wheeling convention eventually organized a new state government for the region, which would be admitted to the Union as the state of West Virginia in 1863.
Due to his victories in western Virginia, McClellan's reputation quickly grew in the North, where the newspapers called him the “Young Napoleon.” Following the Union defeat at the First Battle of Bull Run, he was given command of the Army of the Potomac. Lee was much criticized in the press because of his defeat in Western Virginia. Called by the press and the soldiers “Granny Lee” and “Evacuating Lee”, he was transferred to South Carolina to supervise construction of coastal fortifications. The remaining forces in Western Virginia were organized into the Army of the Northwest until it was incorporated into the Valley District of the Army of Northern Virginia./p>