The summer of 1863 started off disastrously for the Army of the Potomac in the Eastern Theater. In early May, Confederate General Robert E. Lee’s Army of Northern Virginia defeated and humiliated Major General Joseph Hooker’s army at the Battle of Chancellorsville. While both armies reorganized in the wake of Chancellorsville’s massive losses, Lee then maintained the initiative and launched an invasion of Pennsylvania. Throughout June, Lee’s army advanced deeper into Pennsylvania and Northern efforts to stop his progress were ineffective until Major General George Meade replaced Hooker as commander of the Army of the Potomac. On July 1, 1863, Meade and Lee’s large armies collided outside of the crossroads town of Gettysburg, Pennsylvania. The stakes were never higher for either army as the.