Conversation so far:
what were some of Ed McMahon's other roles?
Since 1973, Ed McMahon served as co-host of the long-running live annual Labor Day weekend event of the Jerry Lewis MDA Telethon.
where was the live annual Labor Day weekend event of the Jerry Lewis MDA Telethon with Ed McMahon?
how many years wasEd McMahon a part of the the live annual Labor Day weekend event of the Jerry Lewis MDA Telethon?
His 41st and final appearance on that show was in 2008, making him second only to Jerry Lewis himself in number.

Question: how did he become involved in the telethon?
Self-contained rewrite: how did Ed McMahon become involved in the telethon?