Metropolis of Nature: Railways

Cronon's tended to focus on the railways as a key reason for the outward expansion of the United States.I enjoyed this visual guide of railways and movements.Its difficult to imagine that this was built in a 27 years and this must have created and extremely large vacuum of labor and money to be made leading up to the civil war.Why did the south constantly say that the trans continental would split the country? How do you think this rail would affect these people? These are questions that this reading raised.