Yesterday I published a freelance piece on the ins and outs of time zones. I learned a lot from it, including how complex and contentious they still are (Maine and Massachusetts have been considering getting out of daylight saving time and moving to the Atlantic time zone, and they have a compelling argument), and how daylight saving time emerged from one postman's entomology hobby.

What only glancingly made it into the article was something else I learned: America was divided into its (mostly accepted) time zones in Chicago. Which makes sense. Chicago was and still is the biggest railroad town in the country, and the railroads were, in both the United States and Europe, the catalyst for the creation of time zones. In fact, there's a historical argument that the challenges of scheduling trains inspired Albert Einstein's development of the general theory of relativity:

Einstein's relativity has long been regarded by scholars as a monument to the power of abstract thought. But if Dr. Peter Galison, 48—a Harvard professor of the history of science and of physics, a pilot, art lover and nascent filmmaker—is right, physics and Einstein have flourished more in their connections to the world than in any ivory tower aloofness. And one clue to the origin of relativity can be found in something as mundane and practical as a 19th-century train schedule. "It's in as plain sight as it could possibly be," he said.

As Dr. Galison relates, before the advent of factories began to standardize life, and railroad systems with crisscrossing tracks made it imperative to know which train was where and when, there were too many times, one for every village.

In the last part of the 19th century, the coordination of clocks and the standardization of time had engaged the passions of nations, business leaders, astronomers and philosophers. The patent office in Bern, Switzerland, where Einstein worked, was a clearinghouse for patents on the synchronization of clocks.

In the U.S. in the 1870s there were hundreds of time zones, because localities tended to run on mean solar time, i.e. noon was when the sun was highest in the sky. This meant that time changed in gradients, a complex system captured in gorgeous time tables from the era.

Take this time and distance indicator from 1862: when it was noon in Philadelphia, it was 12:04 in New York, 12:06 in Albany, 12:16 in Boston, and 11:54 in Baltimore. Meanwhile, it was 11:10 in Chicago, 10:59 in St. Louis, and 11:18 in Indianapolis. Synchronizing relative time across cities might have inspired Einstein's thought experiments, but it was a poor way to run a railroad.

Over the course of the mid- to late-19th century, the number of time zones was slowly whittled down as the country moved toward the current system. According to a report in the Tribune from 1882, about a discussion of standard time at the annual conference of the American Society of Civil Engineers, there were "nearly eighty different and arbitrary time standards used by the railroad systems in the United States and in the neighborhood of one hundred, possibly more, so-called standards established by various cities in the Union." The next year, just before the establishment of standard time, the Tribune reported that the railroads had operated on "53 different kinds of time." Not only were there local and train times, they could change independently of one another.

Chicago's local time was determined by the Chicago Astronomical Society, which came into existence in 1862; in 1869, it negotiated a contract with the city for the, um, astronomical price of $1,000 a year (about $18,000 in current dollars), to keep time. Its implementation was delayed by the Great Fire, but the system was resurrected in 1880. A wire connected the Dearborn Observatory, then on the University of Chicago campus, to City Hall, which then sent time signals to the police and fire stations. Jewelers and railroads got the local time from the Western Electric Company, which in turn was believed to get the time from the Dearborn Observatory, but in 1883 the Tribune discovered that the utility had been receiving its time signals from the Allegheny Observatory, for reasons that underscore the complexity of timekeeping in the era.

"The jewelers here complained of irregularities in the time, and threatened to cease taking it if we did not get our time from the Allegheny Observatory. When a complaint would be made we would get the Allegheny time and find a discrepancy, and then we would get Washington time to decide it would invariably turn out the error was in Chicago," the Western Electric vice-president told the Tribune. Furthermore, he told them that the Milwaukee & St. Paul railroad got its time from the Madison Observatory, the Michigan Central got its time from the Ann Arbor Observatory, "and many of the other roads have their time regulated by the other jewelers in the city." (Chicago's first official timekeeper was a jeweler.)

Not only did Chicago have its own local time, it may not have been always correct; meanwhile, trains were running into the city through a tangle of local time zones governed by different time sources.

A solution had been building, though its origins were just as messy. In 1909, William F. Allen, secretary of the American Railway Association and one of the prime movers behind standard time, described how it developed.

When the officials of one important [rail]road desired to change its time-table, which they generally did each spring and fall, they would suggest to the officers of the other roads that a meeting for consultation should be had. Then, sometimes what were called "speed wars" would occur. A road running between two competing points would, without notice to the others, quicken the speed of one or more of its trains. Its rivals would retaliate by putting on still faster trains, when the first road would respond by still further increasing its speed, and so on. Having finally reached the limit of what was then considered safety, a convention would be called and articles of peace agreed upon. Finally, a general arrangement was entered into by roads known as the "trunk lines" by which they agreed not to change time, nor to run any additional trains between competing points, without first conferring with each other. These conferences were known as "Time Conventions."

The first time convention Allen found evidence of was in 1872; it took another nine years for the General Time Convention to even take up the idea of a standard time. Then in 1883 something changed. Perhaps it was that time zones were sweeping the world. In 1880 Britain officially adopted Greenwich Mean Time. The Canadian railway engineer Sandford Fleming and the astronomer and meteorologist Cleveland Abbe, chief scientist of the U.S. Army Signal Corps, began correspondence about a worldwide system of time zones, proving themselves persistent advocates of what Fleming called terrestrial time. Their work was presented at the Third International Geographical Congress in Venice in 1881, the General Conference of the European Geodetic Association in 1883, and the American Association for the Advancement of Science in 1881 and 1882.

Such a system was politically messy, requiring the coordination of governments for which time zones had political symbolism. But the railroads had only the bottom line to consider. So representatives gathered in October 1883 at the luxurious Grand Pacific Hotel for what the Tribune, in the same article, described as both the Time-Table Convention and the General Railway-Time Convention. The deal was all but done—the paper reported that the "large majority" of the railways, representing 78,000 miles of track, had already decided in favor of Standard Time—and the railways agreed to divide the country into four time zones based on Greenwich Mean Time, taking effect a little more than a month later. Localities could follow or get out of the way. For the most part, they followed.

"Never before has so radical a reform as the establishment of the meridian time as the standard throughout the country been accomplished in so short a space of time," the Tribune editorialized on November 26, 1883, eight days after the switch. "When the railroads first commenced to move in this matter it was the general opinion that it would take at least a year or more to make the new system uniform throughout the country. But from the date agreed upon by the Railroad Time-Table Convention that the new system should go into effect on the various railroad lines it has just taken about one week not only to introduce the new system on all the railroads, but to have it accepted generally throughout the country, and from now forward such a thing as local time will hardly be heard of more."

Not quite. Places are still fiddling. Michigan adopted the central time zone in 1885; Detroit moved to the eastern time zone in 1922; the rest of the state moved to the eastern time zone in 1932; then four counties in the Upper Peninsula moved back into the central time zone in 1973. Indiana's adventures with time zones are impossible to summarize. But it was an astonishingly rapid and successful shift, syncing up almost the entire country in the space of a week, with all roads leading back to Chicago.