Before Johnny Carson hosted The Tonight Show…before he hosted the game show he hosted before he hosted The Tonight Show…he had a prime-time variety series on CBS. The Johnny Carson Show ran Thursday nights at 10. It debuted June 30, 1955 and lasted until March 29, 1956…39 weeks but back then, that was considered a flop. In fact, it was a flop that rankled Johnny for a long time and one which he attributed to not controlling his own show and bowing to the direction of others. He vowed to not make that mistake again in his career and set his sights on getting another chance to do that kind of show, only to do it the way he wanted.
It is believed by some who knew Johnny that even after he became a big hit on The Tonight Show, he still — for the longest time — hoped to move from it back to a prime-time series. Once or twice, he even tried to negotiate a deal with NBC where he'd leave Tonight on a certain date and they'd give him a lengthy commitment for an hour in an earlier time slot. He'd start talks about this plan, then agree or decide to put if off for a while and stay in late night.
At some point — I'm guessing mid-seventies — he seems to have decided that hour-long variety shows were no longer the greatest achievement a comedian could have in television, and that it would be a step down from The Tonight Show. So he gave up whatever vengeance-infused dreams he had of a new prime-time Johnny Carson Show and stayed put at 11:30 until he could stay put no longer.
Here's a short monologue from 1955. He says in it he's been doing this show for 2-3 months so that would make this some time in September…