Edwin W. Barnum enlisted 15 July 1861 in Company "E", 4th Iowa Volunteer Infantry, giving his residence as Des Moines, Iowa and his age as 26. He served with that unit, rising to the rank of sergeant before his death at Pea Ridge, March 7, 1862. The Barnum Family gives a death year of 1882, but that is obviously at odds with the information above, from the Genealogical Record of the Barnum Family.
Sergeant Edwin Wesley Barnum, b. April 23, 1835 (son of Nelson Barnum of Sault St, Marie, and Natie Curtiss), was a student at law when the war broke out, entered the USA Vols. and was made sergeant in Co. E, 4th Iowa Infantry. He was killed March 7, 1862, at the battle of Pea Ridge, being struck in the breast by a six pound ball while fighting several yards in front of his line.
The Battle of Pea Ridge, also called the Battle of Elkhorn Tavern, was a bitterly fought Civil War clash in Arkansas, during which 11,000 Union troops under General Samuel Curtis defeated 16,000 attacking Confederate troops led by generals Earl Van Dorn, Sterling Price and Ben McCulloch. Following a fierce opening assault from the rear that almost overwhelmed Curtis' forces, the outnumbered Union troops rallied. After a desperate struggle with severe losses on both sides, Union forces counterattacked on March 8. The Confederates were forced to retreat, thus thwarting their hopes of regaining control of Arkansas.
His death occurred during the Civil War's largest battle west of the Mississippi, fought at Pea Ridge, Arkansas in March 1862. Participating were some 26,000 soldiers. The Union victory dashed Confederate hopes of occupying Missouri.