History of North America

One by product of the development railroads was?

The correct answer is: Standard Time Zones.

Before railroads, every town had its own local time, based on the position of the sun. This caused problems for train schedules, as trains would have to stop and reset their clocks every time they crossed a time zone boundary. To solve this problem, the United States was divided into four standard time zones in 1883. This allowed trains to run on a consistent schedule, and it also made it easier for people to travel and communicate across the country.