A Charlie Brown Christmas was first broadcast in 1965 on CBS. I was 8 years old and I was stunned at the time by the passage of Linus quoting the Gospel of Luke in explaining the true meaning of Christmas. Apparently CBS executives wanted to cut this passage out, but Charles Schulz, normally a fairly non-confrontational man, was adamant that it remain in.
That was the most important battle Schulz waged and won over this first of the Charlie Brown specials, but there were many others. The CBS executives wanted a laugh track, they didn’t like using kid voice actors instead of adult voice actors and they thought that the jazz music throughout the show was too unusual for what they perceived as a show for kids. When the show was finished the executives were horrified and thought they had a major flop on their hands.