To deny the Confederacy continued use of the Shenandoah Valley as a base from which to launch invasions of Maryland and the Washington area, and to threaten Lee's supply lines for his forces, Grant launched the Valley campaigns in the spring of 1864. Initial efforts led by Gen. Sigel were repelled at the Battle of New Market by Confederate Gen. John C. Breckinridge. The Battle of New Market was the Confederacy's last major victory, and included a charge by teenage VMI cadets. After relieving Sigel, and following mixed performances by his successor, Grant finally found a commander, General Philip Sheridan, aggressive enough to prevail against the army of Maj. Gen. Jubal A. Early. After a cautious start, Sheridan defeated Early in a series of battles in September and October 1864, including a decisive defeat at the Battle of Cedar Creek. Sheridan then proceeded through that winter to destroy the agricultural base of the Shenandoah Valley, a strategy similar to the tactics Sherman later employed in Georgia.