As an executive, Lincoln delicately balanced the qualities of compromise and decisiveness. But as commander-in-chief, Lincoln was plagued by a series of generals who were as compromising as they were indecisive. After McClellan's failure to pursue Lee south from Antietam, he was replaced six weeks later by the reluctant Ambrose Burnside. Unfit for top command, Burnside made a tentative march on the south in November of 1862, stalling for over three weeks on the banks of the Rappahannock River before crossing to Fredericksburg. This delay allowed for a Confederate entrenchment, and in the ensuing battle, Burnside was routed by Lee, losing 13,000 men to Lee's 5,000. Once again, the Union forces retreated north, and Lincoln summarily replaced Burnside with Joseph Hooker.
With a third campaign against the Confederates foiled and heavy losses to the Democrats in the midterm elections, a weaker president might have capitulated when France, under Napoleon III, proposed a six month armistice and a series of peace talks in early 1863. But Lincoln and Seward firmly rejected this proposal, and the war effort pushed on as before. Bolstered by reinforcements from the Conscription Act, Hooker marched on the Confederacy at Chancellorsville. This three-day battle, fought in early May, was another resounding defeat for the Union, who lost 17,000 troops in the fighting. Lincoln changed generals yet again, replacing Hooker with George Meade.
Although the Confederates had lost Stonewall Jackson in the fighting at Chancellorsville, they had strengthened their cause with another successful defense of northern Virginia. Encouraged by this result, Lee decided to take up a second offensive against the Union, which he launched from Fredericksburg in early June. Sending Stuart ahead to scout, Lee pushed forward into Pennsylvania, setting the stage for the most renowned battle of the Civil War.
The opening days of July 1863 were crucial to the fortunes of both sides. As they dawned, the Confederacy appeared unassailable, and quite capable of a damaging counter-attack. Less than a week later, on the strength of two Union successes, the tide had turned for the final time, and the South would begin its long and forlorn retreat to Richmond.
With no sign of Stuart, Lee nevertheless decided to attack the Union at Gettysburg on July 1, where three days of vicious fighting resulted in 40,000 casualties. Union forces under Meade held the line repeatedly, and on July 3 Lee retreated, having lost over one-third of his army. Pacified by the carnage, Meade elected not to pursue in the wake of the tattered rebels.
The next day, Grant completed his amphibious attack of Vicksburg after a long siege. With this, the Union established complete control of the Mississippi River, closing the western front conclusively. Celebrating Independence Day back in Washington, Lincoln received news of Grant's success. This critical victory later inspired Lincoln's memorable remark that "the father of the waters again goes unvexed to the sea."