Delevan was born on the 17th of March 1840, in Richmondville, New York, and at the age of 22, he enlisted in the Union Army with the 121st New York Infantry. Nine months later, he was captured during the Battle of Salem Church and was held captive for two weeks. Delevan went on to fight in the Battles of Chancellorsville and Gettysburg before receiving a commission and by March of 1864, he had reached the rank of Colonel. Delevan was leading a regiment of the 30th US Colored Infantry during the Battle of Crater and it was his actions on the 30th of July 1864, that would later earn him the Medal of Honor. The citation reads:

Gallantry in action where he fell, shot through the face, at the head of his regiment.

Delevan survived the wounds to his chest, arms, and face, and he went on to be promoted to Brevet Brigadier General before mustering out of service in December of 1865. He went back to New York and was married to Lana Green in 1870, with whom he had six children. Delevan and family moved to Nebraska, and he worked as a merchant and storekeeper. He received the Medal of Honor on the 22nd of June 1891, 27 years after his actions, and was one of twenty-three to receive the Medal for actions during that battle. On the 19th of December 1918, Delevan Bates died at the age of 78 and he is buried with his family in the Aurora Cemetery in Aurora, Nebraska: section 8, plot 124.