 The 59th fought its first severe action at the Battle of Antietam, where it was part of the ill-fated advance of Maj. Gen. John Sedgwick’s division into the West Woods, near the Dunker Church.In the chaos of that battle, part of the regiment purportedly fired into the rear of the friendly 15th Massachusetts ahead of them.The 59th New York itself escaped the maelstrom after losing 224 men killed, wounded, and missing, including the loss of 8 officers.