Book excerpt: Although McClellan was a brilliant administrator who possessed good strategic sense, the record shows that he was overcautious and consistently overestimated the strength of his adversaries, always demanding more men and supplies before undertaking offensive action. In 1862, McClellan disagreed with Abraham Lincoln and advanced on Richmond from the east instead of moving directly against the Confederates at Manassas, Virginia. Although the Union army was successful during the Peninsular campaign, their failure to take Richmond, the Confederate capital, gave the South new motivation. Dissatisfied with the campaign and McClellan, Lincoln replaced him with Henry W. Halleck as commander-in-chief.