Roy was born in Catlin Illinois, son of Elzia L. Jessup and Edna Snell Jessup. He went to Coyne Electrical College and upon graduating worked many places through out the state. He married Bernice M. Stulginskis in 1931. They moved to Chicago where they had two children. Roy moved back to Westville, Illinois and worked as an electrician at the GM plant in Tilton, IL. He retired from GM in the 1960's and devoted his life to genealogy. He wrote a book called the The Jessup Family, A Puritan-Presbyterian Lineage.