Johnston's effectiveness in the American Civil War was undercut by tensions with Confederate president Jefferson Davis. Victory eluded him in most campaigns he personally commanded. He was the senior Confederate commander at the First Battle of Bull Run in July 1861, but the victory is usually credited to his subordinate, P.G.T. Beauregard. Johnston defended the Confederate capital of Richmond, Virginia, during the 1862 Peninsula Campaign, withdrawing under the pressure of Union Maj. Gen. George B. McClellan's superior force. He suffered a severe wound at the Battle of Seven Pines, and was replaced by Robert E. Lee.