Seinsoth was drafted five times, but he played only one year professionally, never reaching the majors. He died in a traffic collision while on the way to watch the professional football debut of his college friend O. J. Simpson. He died at Harbor General Hospital in Torrance, California. One of the letters received for his funeral was from California Governor Ronald Reagan, who wrote "One thing you know more than anyone is how much better the world is because of your son passed our way.. you have every reason to be proud of him." Rod Dedeaux said, "If Bill Seinsoth had lived, there's a good chance that no one would have ever heard of Steve Garvey." Seinsoth was the subject of a 2016 book by fellow Arcadia High School graduate Steven K. Wagner titled "Seinsoth: The rough-and-Tumble Life of a Dodger" (Sunbury Press).
