Television

Television was the dominant mass media in the United States
9 in 10 households had one television

 There were only 3 channels. Everyone in the family watched the same program. 

Most shows were in black and white in the early 1960s.
Color started to dominate in the mid 1960s and all shows were in color by 1967.

Westerns, situation comedies (sitcoms), and action-adventure shows that made up the majority of network programming.