Robert E. Lee, Confederate Offensive in 1862 (American National Biography)

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. He had Jackson join him with the Valley Army, and, thus reinforced, he conducted a series of attacks against McClellan just outside Richmond in the Seven Days battles of 25 June-1 July.

The battles saved Richmond and transformed Lee from an apparent failure to the hero of the Confederacy. Lee himself was nevertheless disappointed with the Seven Days, because he had hoped to destroy the Army of the Potomac...He progressed in his strategic convictions beyond the belief that the Confederacy must seize the initiative to conclude also that the initiative must be pushed to a decisive, war-ending victory. Otherwise the superior resources of the Union would enable it to outlast local or regional setbacks. The Confederacy must compel the North to recognize its independence rapidly or it would not be able to do so at all.