And before that, who did people talk to? Their neighbours, their colleagues, their fellow church-goers; the people in the same social class as they, from the same region (or even street) as they.
The Dutch concept of columnization is a perfect example of a divided society living in their little echo-boxes. There were Catholic schools, Catholic hospitals, Catholic unions, Catholic societies, Catholic sport organizations, Catholic newspaper and later even Catholic radio and TV. Same for the protestants, same for the socialists, and in lesser degree the same for Liberals (who were a tiny upper-middle class group) and Jews (who most people just ignored as much as they could). My history Teacher told us about how he was not allowed to even talk with kids in his own street because they were of the different religion, and how he had to cycle all the way through town for the Catholic school even though there was a perfectly fine (Protestant) school very close.
People always think the times they live in are definitely worse then those in the past. Please. The people who only listen to those who agree with them on twitter are the same people shouting you would go to hell for reading a Protestant newspaper 50 years ago. Nothing has changed, just the way we experience it.