A native of Pomona, California, Seagren was one of the world's top pole vaulters in the late 1960s and early 1970s. He won six National AAU and four NCAA titles indoors and outdoors. Indoors he posted eight world bests between 1966 and 1969. He was also the Pan American Games champion in 1967. Seagren went on to become an actor, appearing in several movies and television shows, including the controversial sitcom