At exactly noon on this day in 1883, American and Canadian railroads began using four continental time zones.  The standardization of time standards on the continent stemmed from the problems encountered  by the railroad industry in scheduling arrival and departure times as trains made their way across the US and Canada. 

Prior to the establishment of four time zones, the North American continent thousands of time zones, each usually based upon “local time” for a particular town or county.

“Even as late as the 1880s, most towns in the U.S. had their own local time, generally based on “high noon,” or the time when the sun was at its highest point in the sky. As railroads began to shrink the travel time between cities from days or months to mere hours, however, these local times became a scheduling nightmare. Railroad timetables in major cities listed dozens of different arrival and departure times for the same train, each linked to a different local time zone.”  -history.com, railroads create the first time zones

It’s worth noting that the move to standardized time zones was not made by the governments of the United States or Canada, but the railroad industry, which indicates the huge amount of political power that had been amassed by the relatively new industry by 1883.  Congress officially adopted the railroad time zones twenty-five years later, in 1918 and placed them under the supervision of the Interstate Commerce Commission.