Lying astride the border separating the Union and Confederacy, the Alleghenies were among the areas most directly affected by the American Civil War (1861–1865). One of the earliest campaigns of the War was fought for control of the Staunton and Parkersburg Turnpike and for the access it provided to the B&amp;O Railroad. The Battle of Rich Mountain (July 11, 1861) gave the Federals control of the turnpike, of Tygart's Valley, and of all of the territory of western Virginia to the north and west, including the railroad. (Union General George McClellan's victory in this theater would ultimately bring him promotion to commander the Army of the Potomac.) The Federals fortified at Cheat Summit, and the Confederates established strongholds at Camp Bartow and Camp Allegheny. Here they faced each other warily through the fall of 1861 and the following winter. General Robert E. Lee's attempt to attack Cheat Summit Fort (September 12–15, 1861) and Federal attempts to attack Bartow and Allegheny, all failed to change the strategic stalemate. Finally, the harsh, high elevation winter achieved what the troops had failed to accomplish, and in the spring of 1862 both armies moved on down the pike to the Battle of McDowell (May 8, 1862), and then on to fight what became General Stonewall Jackson's Shenandoah Valley Campaign (spring 1862). Two years later, much of this contested area (along with much else) became part of the new state of West Virginia. The very rugged terrain of the Alleghenies was not at all amenable to a large-scale maneuver war and so the actions that the area witnessed for the remainder of the conflict were generally guerrilla in nature.