He entered service Oct 10, 1862 at Athens, Ala in the Artillery Co. of John J. Ward and continued until parolled May 26, 1865 at Decatur. He was drilled at Camp Beulah in Mobile and had artillery practice at Ft. Morgan. He joined the forces opposing Sherman in his march from Chattanooga to Atlanta in May of 1864. He was wounded at Kennesaw Mt. with the same shot that killed Capt Ward and took off Gen Echol's leg. After recuperating, he took part in the defensive battle at Columbus, Ga.
He was sheriff of Limestone County. At that time the jail was in a two-story building on Madison Street. The Sheriff and his family lived downstairs while the prisoners were kept overhead.
From a Newspaper clipping by Bob Dunnavant: "He was 7 when his mother died and he was sent to Athens to live with his grandfather, Thomas K. Gordon. He was wounded in the battle of Kennesaw Mountain. James returned home to find his step-mother and children in 'an almost starved condition' and settled temporary in Athens. His father was in prison in Nashville, TN having been taken prisoner at Selma and refusing to take the oath of allegiance to the United States."
On Sunday April 16, 1865, James Calvin claimed to have fired one of the last shots of the war in the South from the east end of the Upper Bridge at Columbus Georgia.