The regiment was organized in Albany, New York, on May 24, 1861,[2] and was mustered in for a two-year enlistment on June 15, 1861; it was composed of five companies from Herkimer County, two from Steuben, one from Albany, one from Clinton and one from Essex County.

At 7:30 on the morning of September 17, 1862, the Thirty-fourth Regiment left camp near Keedysville, crossed the Antietam Creek and marched westward into the East Woods, now extinct.

Facing Westward being on the extreme left of Brigade line it emerged from the East Woods and soon became heavily engaged with the Confederate forces in its front.

Crossing the open field and the Hagerstown Pike, it entered the West Woods, now also extinct, the line extending North and South of the Dunkard Church.

On May 1, 1863, the day prior to the Battle of Chancellorsville, six companies of the regiment mutinied and refused to fight on the grounds that their two year enlistment terms had expired, although in fact this was still almost two months away.