American Railroads: Explained in 20 minutes

https://en.wikipedia.org/wiki/Erie_Canal

https://en.wikipedia.org/wiki/Baltimore_and_Ohio_Railroad

https://en.wikipedia.org/wiki/Boston_and_Albany_Railroad

https://en.wikipedia.org/wiki/Charleston_and_Savannah_Railway

https://en.wikipedia.org/wiki/Pennsylvania_Railroad

https://www.bts.gov/geospatial/time-zones

https://www.history.com/news/when-did-the-united-states-start-using-time-zones