In his new command, Sigel opened the Valley Campaigns of 1864, launching an invasion of the Shenandoah Valley. He was soundly defeated by Maj. Gen. John C. Breckinridge at the Battle of New Market, on May 15, 1864, which was particularly embarrassing due to the prominent role young cadets from the Virginia Military Institute played in his defeat. After the battle, Sigel was replaced by Maj. Gen. David Hunter. In July, Sigel fought Lt. Gen. Jubal A. Early at Harpers Ferry, but soon afterward was replaced by Albion P. Howe.