Hugh McCugh was born at Hanover, Columbiana County, Ohio, on May 6, 1843. He was of Scottish ancestry and was born from the union of Edward and Elizabeth McCugh. Edward was a Methodist minister.
He lived in Hanover during his early life. He entered Mount Union College upon completion of his studies in the Hanover school system. The talk of war spreading across the nation in the 1860s became a reality in early 1861. Hugh enlisted as a private in Company H, 19TH Ohio Volunteer Infantry on April 27, 1861, at Cleveland and was mustered into the service on May 29, 1861, at Columbus.