Complex sentence: Charlie Brown and his friends appeared on Dolly Madison packages and in television commercials in the 1970s and 1980s, and the bakery was one of the sponsors of the "Peanuts" animated specials during that period.
Split into simpler sentences: Charlie Brown and his friends appeared on Dolly Madison packages and in television commercials in the 1970s and 1980s. The bakery was one of the sponsors of the "Peanuts" animated specials during that period.