Years ago I had a multi band radio that had Ch 1-23, I believe, as part of it to go along with the AM, FM, etc.
My dad and my sister had H.E.L.P., a G.E. CB radio with an antenna you could put on your car’s roof, etc.
In Stephen King’s The Stand, the members of the Boulder Free Zone and others used CB to communicate. It was written in the late 70s.