The New York Central began intermodal container service circa 1923. This was about as soon as it was possible to do so. Basically, that was as soon as a truck that could take a 10,000 pound load was readily available. Other railroads, specifically the Pennsylvania, followed and container service was growing rapidly. It did reduce the railroads' cost of moving the freight by an astonishing amount - around 75%. That's not a "typo". What had cost $1.00 to move in a boxcar system cost $0.25 to move in the new container system. (Those are Interstate Commerce Commission numbers.) The railroads manage to hang on to about 1/3 of the savings. The other 2/3 went through to their customers due to competition.
Who would oppose such a thing? The incredibly stupid US Government, that's who. In 1931 a jerk named Harry C. Ames, an Attorney-Examiner for the ICC, recommended that the railroads be forced to increase their rates on container business. The entire commission went along. (The Attorney-Examiners did the real work at the ICC with the commissioners usually following their recommendations, no matter how stupid they were.) The case was 173 ICC 377. Harry C. should be dug up and shot.
His "recommendation" blocked the railroads from modernizing and locked them into the inefficient loose car system for decdades. This did tremendouse damage to the US economy by driving up logistics costs and began the downfall of the NYC and Pennsy. They were locked into the old loose car sytem by governement regulation.