Before time zones, there was local time. Essentially, whenever the sun at its highest point in the sky is noon. This was particularly difficult for rail travel, because a town that is a few dozen miles away has a slightly different local time, and you can't set a train schedule unless everyone agrees what time is when. Trains also move fast enough that you can notice time zones. Horse and foot travel are too slow for this. The other big thing was the telegraph. With telegraphs, you can now communicate with people who are clearly experiencing a different time.