About William Katt
William Theodore Katt is an American actor and musician. He is best known for his starring role as Ralph Hinkley/Hanley on the ABC television series The Greatest American Hero (1981–1983). Katt first became known for playing Tommy Ross, the prom date of Carrie White in the original film version of Carrie (1976). He was seriously considered for the role, which went to Mark Hamill, and Katt instead starred that year in First Love, playing a college student who experiences his first romantic relationship. He subsequently starred in films such as First Love (1977), Big Wednesday (1978) and Butch and Sundance: The Early Days (1979).
Biography source: Wikipedia. The profile adds birthday-specific historical context from the Celebs Birthday Today editorial database.