In this late war image General Carroll is wearing a double-breasted, lapel coat that is not likely of any regulation pattern. The coat appears to have a slash pocket over the left breast. His kepi has a U.S. wreath on the front, which was a small star above the U.S. This feature is not regulation, but does severe to distinguish him as a general officer and not a staff officer. The kepi has a dark blue velvet band. General Carroll's rank is not indicated by shoulder straps, but by a single star worn on the shoulder. This is in accord with General Orders Number 286 of November 22, 1864.
General Carroll graduated from West Point in 1856 and was serving as a lieutenant in the quartermasters department at West Point when the war began. He accepted an appointment as colonel of the 8th Ohio Infantry and in 1862 while still a colonel was given command of a brigade. He was with the 2nd Corps at Gettysburg, where his counterattacking brigade pushed the Confederates off of East Cemetery Hill after Union General Von Gilsa's brigade broke and the batteries of Weidrich and Ricketts were nearly overrun. This episode received less attention than many other events of Gettysburg, but it was another point at which the Confederate Army had grabbed at victory and almost realized it. He received his long overdue promotion to brigadier general on May 12, 1864. He was wounded multiple times. The loss of his left arm (evident in the photograph) occurred May 5, 1864 during the Wilderness. Carroll is remembered as an energetic officer with a voice that carried on the battlefield.