Complex sentence: Lewis began hosting telethons to benefit MDA in 1952 then from 1966 to 2010, he hosted the annual "Jerry Lewis MDA Telethon" raising over $2.6 billion.
Split into simpler sentences: Lewis began hosting telethons to benefit MDA in 1952. From 1966 to 2010 he hosted the annual "Jerry Lewis MDA Telethon" raising over $2.6 billion.