The first TV sitcom with an all-black cast was Amos 'n Andy which first appeared on television beginning in 1951, running for 3 more years. It was based on a radio show whose black characters were originally played by white actors in dialect. This TV show was quite funny and wasn't that stereotypical; it didn't preach or send a message but, like Sanford and Son, was just about hapless characters who could've been of any race. Still, at that time, there were those who panned it.
In hindsight, however, this show is now given credit being in the van guard of its genre. I don't know who directed or produced it but it wasn't Norman Lear. You can get more information by Googling it, and watching episodes from it on YouTube.