A few summers ago I spent some time hanging out in the archives at Radcliffe College looking at the papers from the Women's Equity Action League, a group that was instrumental in fighting for the passage and enforcement of Title IX in the 1970s and 80s.
I was surprised, but pleased, to see several Peanuts cartoons included in WEAL's files and on some of their educational materials on girls in sports. (I am ignoring here the likely copyright violations.)
Turns out Charles Schultz was a strong supporter of Title IX and girls in sport. And the latest collection of his strips illustrates (pun intended) that. It is a collection of the comics from 1973 thru 1974 and includes a very nice introduction by his friend Billie Jean King. Schultz and BJK bonded over Title IX and Schultz would even drop BJK's name in his strips from time to time. (It was a sign that they needed to touch base.)
So if you are a Peanuts fan, check it out.