In 1865 McCallum participated in the organization of the Funeral and burial of Abraham Lincoln. Following his death by assassination, the body of Abraham Lincoln was brought from Washington, D.C. to its final resting place in Lincoln's hometown of Springfield, Illinois, by funeral train, accompanied by dignitaries. The Department of War designated the route and declared railroads over which the remains passed as military roads under the control of McCallum as director and superintendent of United States Military Railroads. No person was allowed to be transported on the cars except those authorized by the War Department, and the train never moved at speeds of more than an hour to avoid any accidents.