 Further, he states that the two corps in question were not in reserve per existing doctrine as they were manning portions of the line.He additionally notes that McClellan did not display his famed caution at the battle as he attacked an enemy he believed outnumbered him on high ground.The battle was tactically inconclusive, with the Union suffering a higher overall number of casualties, although Lee technically was defeated because he withdrew first from the battlefield and retreated back to Virginia, and lost a larger percentage of his army than McClellen did.