The 23rd New Jersey Infantry Regiment was recruited from various towns within Burlington County, New Jersey, and was mustered into Federal service in August 1862.The regiment trained at Camp Cadwalader in Beverly, before being sent out to join the Army of the Potomac. There, it was brigaded with the New Jersey units that made up the famed "First New Jersey Brigade", which had been reduced to a shadow of its former self due to continual field service and participation in the Battles of Gaines Mill, Second Bull Run, and South Mountain. The arrival of the nearly 1,000-strong 23rd New Jersey and the newly recruited three-year 15th New Jersey Volunteer Infantry greatly replenished the brigade's numbers.