Heckman was born in Pennsylvania and graduated from
Minerva Seminary in 1837. He served in the volunteer army during the
Mexican–American War, becoming a
sergeant by the time he was mustered out of service in 1848. Apart from the Civil War, Heckman spent most of his career as a
conductor for the
New Jersey Central Railroad. Immediately after the Civil War began, Heckman enlisted in the
1st Pennsylvania Volunteer Regiment and was elected captain. Before seeing any action in that regiment, he was appointed major of the
9th New Jersey Volunteer Regiment. On October 8, 1861, he became the regimental lieutenant colonel and joined
Ambrose Burnside's expedition to North Carolina. He fought at
Roanoke Island and was promoted colonel just two days after the battle. He was wounded at the battles of
New Berne and Young's Crossroads. On November 29, 1862, he was promoted to brigadier general of U.S. volunteers. When General Burnside left for Virginia, he left Union forces in North Carolina under the command of
John G. Foster. In the winter of 1862, Foster led an expedition against the
Wilmington and Weldon Railroad at
Goldsborough, North Carolina. General Heckman led a brigade in Foster's expedition at the battles of
Kinston,
White Hall and
Goldsborough. Throughout most of 1863, Heckman was in command of the District of
Beaufort, briefly commanding the Union defenses at New Bern. During the fighting in Fort Harrison, XVIII Corps commander
Edward O. C. Ord was severely wounded and carried from the field. Heckman then assumed command of the corps. With this change in command at a crucial point, the fighting ground to a halt, and the Union forces constructed a defensive line. After an undistinguished show of leadership during the fighting on September 29, army commander
Benjamin F. Butler decided to replace Heckman in command of the corps with his chief of staff,
Godfrey Weitzel. Returning to command his division, Heckman helped repulse the Confederate attack the following day. In December, Heckman was transferred to command the 3rd Division in the newly created
XXV Corps. Briefly from January to February in 1865, he was in command of the XXV Corps, but resigned from the army on May 25, 1865. Heckman returned to work for the New Jersey Central Railroad as a conductor and railroad dispatcher following the war. ==See also==