How did they hang out or plan on going somewhere?
Widespread cell-phone use is less than 20 years old, so while there are historical answers to be had here, really, this is a question that you can get many, many answers to from just about anyone over 30. While I'm not removing this thread, you might be better served asking this on a subreddit such as /r/AskReddit, where people can respond with the personal anecdotes we would remove here.