Edgar was born on the 30th of November 1847, in New Richmond, Ohio, and at the age of 16, he enlisted in the 153rd Ohio Infantry during the American Civil War. He stayed in the Army after the war and served on frontier duty with the 8th US Cavalry, and it was his actions on the 30th of May 1868, that would earn him the Medal of Honor. The citation reads:

With two other men he volunteered to search for a wagon passage out of a 4,000-foot valley wherein an infantry column was immobile. This small group passed six miles through hostile Apache terrain, finding the sought passage. On their return trip down the canyon they were attacked by Apaches, who were successfully held at bay.

Edgar received the Medal of Honor two months later on the 28th of July 1868, and he remained in the Army until 1893. Edgar R Aston died on the 14th of April 1932, at the age of 84 and he is buried in the Tate Township Cemetery in Bethel, Ohio: Section 7, Lot 40.