On June 30, Confederate forces under Lieutenant General A.P. Hill spotted Federal troops in Gettysburg, Pennsylvania. Hill decided to send a large scouting party the following morning to get more information on the size of the enemy army. The Union’s Army of the Potomac had a change in leadership just three days before the battle began. Major General George Meade took charge after Major General Joseph Hooker resigned. Most of Meade’s army was assembling to the south of Gettysburg along a section of hills and ridges that made strong defensive positions. Hill’s troops met the Union’s advance forces west of the town where the Northern cavalry was guarding ridges and buying time for the rest of the army to arrive. Confederate troops attacked from the north and northwest. Though the Union held for a while, they were forced to retreat through the streets of Gettysburg.