James Judson Van Horn, army officer, was born in Mount Gilead, Marrow County, Ohio, in 1834. He was a cadet at the United States Military Academy at West Point, New York, from 1854 to 1858. He stood fourteenth in his class of twenty-seven at West Point and upon graduating was promoted to brevet second lieutenant of infantry. He was promoted to second lieutenant in 1858 and served in the garrison at Fort Columbus, New York, until 1859, when he was placed on frontier duty at Fort Davis, Jeff Davis County, Texas. Van Horn commanded Company F of the Eighth Infantry, which also occupied Van Horn Wells, in what is now Culberson County. The wells were known to Indians and travelers on the San Antonio-El Paso Road as a dependable watering place and were the site of a stage station on the Butterfield Overland Mail route. After the outbreak of the Civil War Fort Davis was seized by Confederate troops, and Van Horn was taken prisoner on May 8, 1861. He spent eleven months as a prisoner of war before being exchanged on April 4, 1862; while a prisoner he was promoted to first lieutenant. He served in various other capacities during the Civil War. He was aide-de-camp to the provost marshal general of the Army of the Potomac in 1862–63. He was promoted to captain in February 1862 and was present at the battle of Antietam in September of that year. In 1863–64 he was mustering and disbursing officer at Trenton, New Jersey; he served in the Richmond campaign and operations before Petersburg, Virginia, in 1864. He was promoted to brevet major in June 1864 for his service at the battle of Cold Harbor, Virginia, and in 1865 was aide-de-camp to Maj. Gen. W. F. Smith, who commanded the Eighteenth Army Corps.
In the years immediately following the Civil War Van Horn served in Raleigh and New Bern, North Carolina; Charleston, Columbia, and Summerville, South Carolina; and David's Island, New York. In 1872 and again in 1873 he was on frontier duty with the Yellowstone expedition. He also served at Fort D. A. Russell and Camp Robinson in Wyoming, the Red Cloud Agency in the Dakota Territory, and Fort Whipple and Fort Mojave in Arizona; at the last he was commander. He was promoted to major in 1879. In the early 1880s Van Horn commanded the Mount Vernon Barracks in Alabama and the garrisons at Fort Wingate, Fort Union, and Fort Stanton in New Mexico. He commanded a regiment at Fort Snelling, Minnesota, in 1885 and 1886 and was promoted to lieutenant colonel in June 1885. He commanded the troops at Fort Shaw in Montana from 1888 to 1890 and served at Fort Keogh, Montana, in 1891. He was promoted to colonel in April 1891 and commanded a regiment at Fort McKinney, Wyoming, until 1894. After four more years at Fort D. A. Russell, Wyoming (not to be confused with Fort D. A. Russell in Marfa, Texas), Van Horn briefly commanded the Department of Colorado in Denver (March and April 1898). He commanded a regiment and infantry division at Camp Thomas, Georgia, and the first brigade, second division, Fifth Corps, at Tampa, Florida, and en route to Santiago de Cuba until June 1898. He was subsequently on sick leave until August 30, 1898, when he died at Fort D. A. Russell, Wyoming. His son later rose to the rank of colonel in the army and from 1911 to 1915 was stationed at Fort D. A. Russell in Texas.