While Lewis (and Martin) had done telethons for MS before as one-offs, today is the 60th anniversary of the first 24-hour Jerry Lewis Labour Day Telethon. 

While it's now well known that Lewis was generally an awful human being, that wasn't well known at the time (except by Dean Martin, his children, and numerous women)

https://www.cbsnews.com/video/looking-back-at-the-jerry-lewis-muscular-dystrophy-telethon-after-60-years/