I don't know about the 50s, but in the 70s I recall the 3 networks (ABC, NBC, CBS -- here, we got 2 of each, from NYC and Philly) plus PBS and maybe another station or two.

VHF went from Channels 2-13, and there were a couple UHF stations that came in as well. Not much variety.

BTW, there was an antenna on the roof that we had to rotate with a dial to point to where we wanted (NYC or Philly or wherever). Pain in the butt.

We got cable in the early 80s which had a WIRED remote with 3 rows of 13 channels, but not all of them were used I don't think. But we had HBO, MTV, etc.