During the Civil War he was a Corporal in Company "I", 14th Regiment, Connecticut Infantry. He was captured by the Confederates at Morton's Ford, Virginia, on February 6, 1864 and died on October 11 of that year while confined at the infamous prison camp at Andersonville, Georgia.
Andersonville Prisoners of War about Philetus M. Barnum. Surname: Philetus M. Barnum. Rank: Corporal; Company: I; Regiment: 14; State: CT; Arm of Service: Infantry; Death Date: 11 Oct 1864; Cause Of Death: Dysentery C.; Remarks: P. M. Barnum [2]; F. Burnham [3]; Reference: p 1 [3]; p 53 [14]; p 579 [45]; Location of Capture: Morton's Ford, VA; Date of Capture: 6 Feb 1864; Page: 324; Notes: Burnham; More Information: No; Code: 20682; Grave: 10682.
American Civil War Soldiers about Philetus Barnum. Name: Philetus Barnum; Residence: Middlebury, Connecticut; Enlistment Date: 11 Aug 1862; Side Served: Union; State Served: Connecticut; Service Record: Enlisted as a Private on 11 August 1862. Enlisted in Company "I", 14th Infantry Regiment Connecticut on 23 Aug 1862. Promoted to Full Corporal on 1 Nov 1863. Died of disease as a POW Company "I", 14th Infantry Regiment Connecticut on 10 Oct 1864 at Andersonville, GA. Sources: 5,43,206.
Civil War Prisoner of War Records, 1861-1865. about Philitus M. Barnum. Name: Philitus M. Barnum; Side: Union; Roll: M1303_3; Roll Title: Selected Records of the War Department Commissary General of Prisoners Relating to Federal Prisoners of War Confined at Andersonville, GA, 1864-65.