During the US Civil war Isaac E. Barnum was a seaman aboard USS Great Western and USS Collier. His widow received a pension as a Navy Widow.
USS Great Western (1857) was a steamer acquired by the Union Navy during the US Civil War. She was used by the Union Navy as an ammunition ship. Great Western, a sidewheel steamer, was built at Cincinnati, Ohio, in 1857 and was purchased by the US War Department 10 February 1862. She was used from the date of her purchase by the Western Flotilla but was not officially transferred to the Union Navy until 30 September 1862. Great Western was used as an ordnance boat for the Navy on western waters, and in that capacity operated from Cairo, Illinois, to various points on the Mississippi River and its tributaries. She supplied ships at the mouths of the White and Arkansas Rivers with ammunition and ordnance, and occasionally fired at Confederate batteries ashore in the almost-daily engagements in keeping open the far-spreading river highway system by which the Union divided and destroyed the South. While with the Mortar Flotilla, 30 July 1862, she fired on cavalry attacking the boats near the mouth of the Arkansas River and succeeded in driving them off. During 1862 and the first half of 1863, the overriding concern of Union forces was the capture of Vicksburg, and Great Western spent much of her time during this period near the mouth of the Yazoo River above the city in support of combined operations there. She provided support for the joint attacks of December 1862 above the city, and remained in the area until that Confederate stronghold fell in July 1863. Following the fall of Vicksburg, Great Western continued her duties as supply ship for the squadron, being stationed at Skipwith's Landing, Mississippi, and Goodrich's Landing, Louisiana. In July 1864 she was sent back to Cairo, Illinois, to act as a receiving ship. Great Western was transferred as receiving ship, Mound City, Illinois, in March 1865, and was subsequently sold at auction there to John Riley 29 November 1865.
USS Collier was a sternwheel steamer built at Cincinnati, Ohio, in 1864 as the Allen Collier and purchased by the United States Navy on 7 December of that year. The ship was commissioned as the USS Allen Collier on 18 March 1865 and renamed to be USS Collier soon thereafter. Navy records occasionally continued to refer to the ship by her original name, Allen Collier and more frequently by a name which she never carried officially: A. Collier. Collier patrolled the Mississippi River until the end of the American Civil War. She was decommissioned on 29 July 1865 and sold into civilian service later that year.
Isaac and family moved from Michigan to Colorado and are enumerated in 1880 in Denver, Arapahoe County, Colorado:
I. E. Barnum 37 b. Michigan
Mary. E. Barnum 35 b. Michigan
Edwin A. Barnum 8 b. Michigan
A. J. Abbott 55 b. NY (mother in law)
In 1900, Isaac and Mary were still living in Denver, Colorado. According to Colorado death records, Isaac died in Denver on March 22, 1904.
Grave stone in Fairmount Cemetery, Denver, Colorado:
Isaac Edwin Barnum 1842-1904
Mary Abbott Barnum his wife 1843-1922