Every country in the world concluded that railway service -- passenger *and* freight -- should be nationalized, because it works better as one integrated system.
Then the US, probably under the influence of leaded gasoline poisoning their brains, passed the Esch-Cummins Act of 1920 and re-privatized the railways. The same year they elected Warren G Harding. Even that act recommended a form of central administration similar to the 1923 Grouping in the UK, but it didn't happen, because America in the Roaring Twenties was run by drunken, drug-addled fools... at best!