He was born in Sioux Falls, Dakota (now South Dakota), and was a son of Fannie (Kingsbury) Grigsby and Melvin Grigsby, a prominent South Dakota political and military leader.
He was born in Sioux Falls, Dakota (now South Dakota), to Fannie (Kingsbury) Grigsby and Melvin Grigsby, a well-known leader in the state's politics and military sectors.