At the end of June, Lee began a series of attacks that became known as the Seven Days Battles. The first major battle, at Mechanicsville, was poorly coordinated by Lee and his subordinates and resulted in heavy casualties for little tactical gain. However the battle had a significant impact on McClellan's nerve. The surprise appearance of Maj. Gen. Stonewall Jackson's troops in the battle (when they had last been reported to be many miles away in the Shenandoah Valley) convinced McClellan that he was even more outnumbered than he had thought. He reported to Washington that he faced 200,000 Confederates, perhaps due to a false report on the arrival of another Confederate army P.G.T. Beauregard. The number of men McClellan was actually faced varies, with Joseph Harsh in "Confederate Tide Rising" placing Lee's army at 112,220 men compared with the 105,857 under McClellan.