On the evening of June 28, 1863, the Third Corps of the Army of the Potomac under Major General Daniel Sickles rested on the road between Walkersville and Woodsboro, while to the south near Ceresville on the same road the Twelfth Union Corps under Major General Henry Slocum was camped. At four o'clock on the morning of June 29 these Federal corps moved north toward Taneytown, joined ahead of the Twelfth Corps by the Union Artillery Reserve under Brigadier General Robert O. Tyler. At 8:00 am, the headquarters train of the newly promoted commander of the Army of the Potomac, Major General George G. Meade, and his staff joined the northbound column. From early that morning and through the day, one third of the Union army marched through Woodsboro on the way to Gettysburg, and as thousands of soldiers and hundreds of horses, mules, wagons, cannons, and ambulances passed, town residents greeted them with encouragement, fresh food, and water. Three days later on July 1, the citizens of Woodsboro could hear the thunderous cannonade twenty eight miles away that opened the hostilities of the third day of the Battle of Gettysburg.