CST plaque
CST plaque Credit: Andrea Bauer

Believe it or not—I have a hard time imagining it myself—most towns used to maintain their own time based on the position of the sun, with “high noon” being the only hour that was anywhere close to precise, even though it wasn’t anywhere close to precise. This proved to be problematic for scheduling anything, and scientists in Britain and the United States proposed the idea of a standard time system in the early 19th century. But nothing changed until corporations realized that sundial timekeeping was bad for business. While railroad executives embraced a standard time system in Britain by 1847, Americans continued to squint at the sun for decades. Finally, in October 1883, railroad executives gathered in Chicago’s Grand Pacific Hotel—now the Continental Bank building and location of the commemorative plaque—and agreed to divide the country up into four standard time zones. The system went into effect on November 18 with a telegraph from the University of Pittsburgh at noon. But then as now, the federal government was slow to recognize what was already a reality for many of its citizens: Congress didn’t officially adopt the system until 1918.