[oh_sigh]

Connecting the coasts via trains would not have been possible with the millions of bison that used to inhabit the west. Either because of the bison directly destroying track, or interaction with the Natives who hunted the bison and were hostile towards Americans.

[gliboc]

Damn bisons destroying our fine tracks and bringing Indians with them; let's wipe out their species!

[oh_sigh]

I don't know what point you think I'm arguing, but I am saying what happened historically. The US would have had a much harder time maintaining their gains from the Mexican-US war less than 20 years earlier(and may have ultimately lost California et al back to Mexico) if they were not able to connect the west coast to the east via rail.