It was the "Smoot–Hawley Tariff Act" that was a disaster because when European nations responded with tariffs on American goods global trade plunged by roughly two thirds
<span> from 1929 levels.</span> This was viewed as exacerbating the Great Depression.
The development that probably hurt it is the reduction of open range herding. In history, people could just let their cattle roam freely and find food since the plains were huge and nobody lived in them. Nowadays, this can be problematic because there are more and more people and settlements and roads with cars so free range herding has been drastically reduced which cost the herders a lot.
In the US, Democrats and Republicans beliefs to two major political parties
It left fewer british troops to fight in north america