The Photographic History of The Civil War: in ten volumes, Thousands of Scenes Photographed 1861-65, with Text by many Special Authorities, Volume 2: Two Years of Grim War.
Francis Trevelyan Miller, Ed.

It was the month of April, and field and woodland had begun to put on the bright colors of spring. There was activity about the Federal army headquarters that indicated a renewal of hostilities. The hospitals had been well cleared, the forces had been recruited, ammunition and arms replenished and put in order, horses groomed and well fed, uniforms renewed, and the Army of the Potomac was in excellent condition to advance against its foe. President Lincoln had visited the camp, and reviewed the army, thrilling the men with his inspiring presence and personality. It was well known that he had a very deep concern in the welfare of the soldiers. After the review he asked, “What will become of all these men when the war is over?” His parting admonition to Hooker was this wise advice, “In your next battle, put in all your men.” By a strange fatality that is just what Hooker failed to do, and a great misfortune overtook his army.

Hooker abandoned Burnside's method of organization. Under “Fighting Joe,” instead of three grand divisions, there were seven army corps, each under a major-general, and a cavalry corps. At this time the Union forces aggregated between one hundred and twenty-five and one hundred and thirty thousand men; Lee's forces were estimated at about sixty thousand. Hooker's corps commanders were: Reynolds, in command of the First; Couch, the Second; Sickles, the Third; Meade, the Fifth; Sedgwick, the Sixth; Howard, the Eleventh; Slocum, the Twelfth, and Stoneman, who was in command of the cavalry corps.

Hooker conceived, a plan of campaign which was ingenious and masterful, and had he carried it out there would have been a different story to tell about Chancellorsville. The plan was to deploy a portion of the army to serve as a decoy to Lee, while the remainder of the host at the same time