The US TRAINS HISTORY
In terms of product there were a number of trends. One was the advent of still smaller scales. OO and HO gauge grew from a collaboration between Bing and Basset Lowke, designed by Henry Greenly, for a table top toy. These first models were really just toys, and the same tooling was used for UK, US and German outline trains. So the scale was a bit debatable. In fact as a toy the Bing Table Top system was not a runaway success, but what it triggered was a great deal of interest by adult modelers in this size of train. As a result two scales emerged HO 1 87 scale and OO 1 76 both in Britain using the same track gauge.
This links with the second trend, model railways as a hobby, and not just for the rich enthusiast, came of age in Britain in the 1920s and was successfully taken up in the US in the 30s. This saw the publication of modelers magazines, an emphasis on home construction and better standards, but also the growth of smaller manufacturers aimed squarely at this adult enthusiast rather than toy market. In the US in particular this led to the early adoption of standards suitable for modeling the NMRA was founded in 1934.
The toy makers took notice of these developments. While most toy trains were sold for junior, they were sold to parents. And if Dad could be enticed to be a more active player, then perhaps more would be bought. Whatever the influence as the 30s went by the better toy trains became much more realistic, adopting shapes, colors and markings much more like the real thing. By 1938 in US, Germany and Britain there were second generation OO or HO scale systems from major toy makers that set new standards in realism. And then came a second world conflict.