Following Chancellorsville, Davis finally reinforced Lee to the strength the general believed necessary for a new invasion of the North. On 3 June 1863 Lee set out for Pennsylvania, but he did so without Stonewall Jackson, who had died on 10 May of complications from wounds suffered at Chancellorsville.

In March [1862], [General George] McClellan had moved his main force by sea from Washington to Fort Monroe; then he began an advance toward the Confederate capital by way of the peninsula between the York and James rivers. On 31 May, General Joseph E. Johnston, commanding the Confederate forces opposing him, was wounded at the battle of Fair Oaks or Seven Pines. The next day Lee succeeded to Johnston's command, which he promptly designated the Army of Northern Virginia. Lee applied his principles of concentrating force and seizing the initiative.

On 18 April [1861], following the bombardment of Fort Sumter on 12-14 April, Francis Preston Blair, Sr., on behalf of President Abraham Lincoln, directly asked Lee whether he would take command of an enlarged U.S. Army. But Lee reiterated what he had said to [General Winfield] Scott. On 20 April, having learned that Virginia had seceded two days earlier, Lee submitted his resignation. It was a painful decision but one that in its expression of loyalty to home and kindred has commanded sympathy even from those who cannot admire it.

As Mary Lincoln's dresser, Keckley prepared her for every public occasion; as her confidante, she shared her anxieties; as her traveling companion, she went to the Gettysburg dedication and toured Richmond after the city fell; and, as her attendant, she cared for her after her son Willie's death and her husband's assassination. When Mary Lincoln left the White House in 1865, Keckley accompanied her to Chicago. After seeing the family settled, she returned to Washington, D.C., where she reopened her dressmaking business.