Final answer:
The Transcontinental Railroad led to the creation of time zones due to varying arrival and departure times of trains. In 1883, the United States was divided into four standard time zones, which later expanded to six, making interstate business and travel much easier.
Step-by-step explanation:
The Transcontinental Railroad led to the creation of time zones due to varying arrival and departure times of trains. Prior to the development of the railroad network, each community in the United States had its own local mean time. However, as the railroads expanded and connected communities, there was a need for standardization. In 1883, the United States was divided into four standard time zones, which later expanded to six, making interstate business and travel much easier.