McClellan, George Brinton

(1826–1885) played an important role early in the war by raising a well-trained and organized army for the Union. McClellan was meticulous in his planning and preparations, but these characteristics may have hampered his ability to challenge aggressive opponents in a fast-moving battlefield environment. He repeatedly overestimated the strength of enemy units and was reluctant to apply principles of mass, frequently leaving large portions of his army unengaged at decisive points.