Time keeping in the United States, indeed, in many parts of the world, was very much a local option based on the movement of the Sun, until railroads began to cross great distances in short amounts of time. The variations in local times caused confusion to travelers and employees alike, so in 1883, the railroads established a standardized time for the country, allowing for movement of the Sun by creating time zones.
Some areas were reluctant to have big business, in the form of railroads, dictating something as personal as time, but by the time of World War I, so much of the country had accepted it that when the Calder Act was passed in 1918, it was just a legal acknowledgment of what was common practice. However, the Calder Act also established Daylight Saving Time, which did not meet with approval by many and was repealed in 1919.
The advent of World War II resurrected the idea of Daylight Saving Time, making it year-round in an effort to conserve energy. The end of the war signaled the end of Daylight Saving Time as a standard, but communities were allowed to use it as a local option, usually ...