Which U.S. president replaced Joseph Hooker with George Meade before Gettysburg?

Abraham Lincoln replaced Joseph Hooker with George Meade as commander of the Army of the Potomac just before Gettysburg. Meade received the appointment on June 28, 1863, only three days before the battle began.

The change followed worsening relations between Hooker and the Lincoln administration. Hooker had commanded the Army of the Potomac during the Union defeat at Chancellorsville, after which Lee gained the initiative and began moving north. During the Gettysburg campaign, Hooker also argued with General-in-Chief Henry Halleck and demanded control of the Union garrison at Harpers Ferry.

When Lincoln and Halleck refused that demand, Hooker offered his resignation, which they accepted. Lincoln then selected Meade, a Pennsylvania-born major general who had commanded the Army of the Potomac's V Corps. Meade had not expected to receive the army command and had only a short time to understand the developing operation.

Meade organized the Union army around strong defensive ground at Gettysburg and successfully repelled Lee's attacks. He was later criticized by Lincoln for allowing the Confederate army to escape after the battle, but he remained commander of the Army of the Potomac for the rest of the war.