During the Gettysburg Campaign, the 2nd Vermont Brigade was one of four brigades sent from the Capital to join the Army of the Potomac as it pursued Robert E. Lee into Pennsylvania. Stannard's command left the Washington defenses on June 25. Marching 18 miles a day for a week, the brigade reported to the 3rd Division of the I Corps. The I Corps had fought, and lost, heavily in the first day of the Battle of Gettysburg, July 1, 1863. Three regiments of Stannard's men arrived only after the fighting ceased that day, adding to the division's depleted ranks. (The other two regiments, the 12th and 15th Vermont, had been detached to guard wagon trains.)