Some areas only had one or two stations!
If you lived in LA or NYC you might have had 4!
The "independent" and PBS stations started coming into existence in the later 60s...and once people noticed how hard it was to get UHF with an indoor antenna...the early 70s brought along a huge increase in the number of outdoor rooftop antennas.
Seven T.V. stations in N.Y.C.; 2 (CBS),4 (NBC),5 (DUMONT),7 (ABC),9 (?) ,11 (WPIX), and 13 (PBS).