Today in History, November 18, 1883:
The origin of time zones.
American railroads were hardly ever on time. Each depot was on a different time, since they used the path of the sun to determine what time it was. As a result, American railroads established a system of “time zones”, so that more of the country would be on the same time.
East, Central, Mountain and Pacific. Eventually cities and then the entire country would adopt the system.