 Secretary Stanton ordered McClellan to report to Trenton , New Jersey , for further orders , although none were issued . As the war progressed , there were various calls to return McClellan to an important command , following the Union defeats at Fredericksburg and Chancellorsville , as Robert E. Lee moved north at the start of the Gettysburg Campaign , and as Jubal Early threatened Washington in 1864 . When Ulysses S. Grant became general @-@ in @-@ chief , he discussed returning McClellan to an unspecified position . But all of these opportunities were impossible , given the opposition within the administration and the knowledge that McClellan posed a potential political threat . McClellan worked for months on a lengthy report describing his two major campaigns and his successes in organizing the Army , replying to his critics and justifying his actions by accusing the administration of undercutting him and denying him necessary reinforcements . The War Department was reluctant to publish his report because , just after completing it in October 1863 , McClellan openly declared his entrance to the political stage as a Democrat . 
