Have Any Famous Artists Gotten Their Training Via Correspondence Schools?

When I was a kid, comic books and TV ads for artist/drawing schools abounded. These seemed to be low-rent operations-you paid a fee for a correspondence course in draing/painting, etc.
Were these schools real or just a swindle?
Did anyone actually become a recognized artist from taking these courses?

I can’t recall the names, but some well-known comic book artists of the 40s took art courses by mail.

It looks like Charles M. Schutz took correspondence courses (from the same people who put out the ads you remember). He worked for them for a time before striking out on his own.

Robert and Charles Crumb messed around with that “Draw Me” correspondence course in interesting ways. I don’t know if they got any training out of it, but they sure had fun. Some of their work from back then is in the movie Crumb.

They used to have you draw Tippy. Now they use this guy.

I still see the ads for this place(the one with Tippy). I have no idea how what they do, but they must make money if they are still in business.