History of time in the United States
On November 18, 1883, United States and Canadian railroads instituted standard time in time zones. Before then, time of day was a local matter, and most cities and towns used some form of local solar time, maintained by some well-known clock (for example, on a church steeple or in a jeweler's window).
Source: Wikipedia — History of time in the United States (CC BY-SA 4.0)