(1834 - 1898)
Home State: Ohio
Command Billet: Staff Officer
Branch of Service: Infantry
He graduated in July of 1858 from the US Military Academy at West Point and entered service in the 8th US Infantry. He served on the frontier in Texas before the War. After Texas seceded in April 1861, he and a number of US Regulars were held as Prisoners of War at San Antonio. While still a POW in February 1862 he was promoted to Captain. He was released in April 1862 and came east to Washington, where he obtained an assignment on the staff of the Provost Marshal of the Army of the Potomac in June.
On the Campaign
In Maryland he was Assistant Provost Marshal General, and was present at South Mountain and Antietam.
The rest of the War
He continued as APMG to 4 July 1863, the last month of that period on sick leave. He was a Mustering Officer at Trenton, NJ until April 1864, and thereafter staff officer to General W.F. Smith (IIXX Corps).
After the War
He served after the War at posts in the Carolinas and New York until he was sent west in 1872. He was promoted Major in 1879 and Lieutenant Colonel - still in the 8th US Infantry - in 1885. In those years he was stationed in Wyoming, the Dakotas, Arizona, and New Mexico. He was promoted to Colonel and commander of the 8th Infantry in 1891, and remained in the west - Montana and Wyoming - until the advent of the Spanish American War in April 1898.
He was "injured in disembarking before Santiago" (Cuba) in June, went on sick leave, and died at Fort D. A. Russell in August 1898.
References & notes
Service history from Cullum1 (Van Horn's number is 1811), with further bio details from the Handbook of Texas2. The photograph above is from one in the collection of the University of Texas at Austin, and was published online in an article from the Southwestern Historical Quarterly. It's a group picture taken of Federal POWs at San Antonio in 1861.
1834; Mount Gilead, OH
08/30/1898 near Cheyenne, WY
1 Cullum, George Washington, Biographical Register of the Officers and Graduates of the US Military Academy, 2nd Edition, 3 vols., New York: D. Van Nostrand, 1868-79 [AotW citation 945]
2 Ellis, L. Tuffly, and James W. Pohl, and Ron Tyler, Editors in Chief, The Handbook of Texas, Published 1999, <http://www.tshaonline.org/handbook/online/index.html>, Source page: /articles/VV/fva7.html [AotW citation 946]