Seawell was born in Atlanta, Georgia in 1916 and studied photography at the Rochester Institute of Technology graduating with honours in 1940. He served with the Army Signal Corps in Los Angeles making nearly fifty training films.
He joined leading West Coast photographer Paul Hesse and started taking photos for movie studios and fan magazines. Seawell also took photos of other public figures such as President Lyndon B. Johnson and the Duke and Duchess of Windsor. Seawell also took photos for album covers for well-known singers as Johnny Mathis and Peggy Lee. Seawell also took the memorable photo of Sam Cooke for his final studio album Ain't That Good News in 1964.