In October of 1883, railroad officials met in Chicago to standardize American timezones.

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Chicago had long been a transportation hub, and the country's some three hundred time zones -- in addition to the fact that most cities determined local time on their own -- had become a problem in scheduling trains.

Timezones were established in Europe a few decades prior, but the US railroads were reluctant to change. The change was made official on November 18, 1883, about a month after their meeting. A signal, marking the exact time, was sent to the major railroads via telegraph.

(Not to be confused with Daylight Savings, an idea which Ben Franklin had while in Paris in 1784.)