Both the western portion of the Manassas Gap Railroad and the Winchester and Potomac Railroad were under Union control by the spring, and were going to be used to support Union operations in that area as part of a plan developed by Major General George B. McClellan. McClellan's plan was to connect the Manassas Gap Railroad and the W&P Railroad with a line between Winchester and Strasburg, creating a complete circle of rails from the Union capital at Washington, D.C., to the Shenandoah Valley by either the B&O or O&A.