After his resignation from the U.S. Army, Julius A. De Lagnel was appointed a captain of artillery in the Regular Army of the Confederate States. In June 1861, he was assigned as chief of artillery to Brigadier General Robert S. Garnett, commander of the Army of the Northwest. Garnett had been sent to reorganize the Confederate force in the western counties of Virginia after their rout at the Battle of Philippi and to hold the area for the Confederacy. De Lagnel defended the crest of Rich Mountain with a force of four companies and one gun during the Battle of Rich Mountain, July 11, 1861. The main Confederate force did not immediately know that De Lagnel's men were under attack by a superior force commanded by Brigadier General William S. Rosecrans. De Lagnel's force eventually was overwhelmed. After De Lagnel used the sole artillery piece to fight by himself for a period of time, he was wounded and hid in a thicket in an effort to escape from the Union troops. He first escaped from the battlefield to a mountaineer's cabin. After two days of recuperation, he tried to return to Confederate lines disguised as a herder. Union troops detected, identified and captured him near Laurel Hill, Virginia on July 13, 1861. On December 18, 1861, De Lagnel was exchanged for Union Brigadier General James B. Ricketts.