American railroads maintained many different time zones during the late 1800s. Each train station set its own clock making it difficult to coordinate train schedules and confusing passengers. Time calculation became a serious problem for people traveling by train (sometimes hundreds of miles in a day), according to the Library of Congress. Every city in the United States used a different time standard, so there were more than 300 local sun-times to choose from. Railroad managers tried to address the problem by establishing 100 railroad time zones, but this was only a partial solution to the problem.History.com explains the miracle of the free market:
Operators of the new railroad lines needed a new time plan that would offer a uniform train schedule for departures and arrivals. Four standard time zones for the continental United States were introduced on November 18, 1883.
Efficient rail transportation demanded a more uniform time-keeping system. Rather than turning to the federal governments of the United States and Canada to create a North American system of time zones, the powerful railroad companies took it upon themselves to create a new time code system. The companies agreed to divide the continent into four time zones; the dividing lines adopted were very close to the ones we still use today.The miracle of voluntary cooperation.
Most Americans and Canadians quickly embraced their new time zones, since railroads were often their lifeblood and main link with the rest of the world. However, it was not until 1918 that Congress officially adopted the railroad time zones and put them under the supervision of the Interstate Commerce Commission.