How did the environment of the American Fur Company change in the 1930s? What deep historical forces are implicated in these change?
That's a question about a very specific company, and I need some more information and context in order to give you exactly the help you need, but let me try it from this perspective.
In the 1930s the United States was in the death grip of the Great Depression. If we look at what that means, we can see 25% unemployment (as opposed to 10.1% now in the "Great Recession"). 300,000 people live on trains crossing the country. 900 banks were closing every year. The Socialist Party was gaining membership.
In that environment there were tensions between the rich and the poor. Wealthy people did just fine during that time, in fact with deflation, times got a little better for them. So they could afford the furs they had always bought, but it was difficult for some of them to wear fur in public when so many people were lined up in soup kitches - that is, it became less fashionable to own one. And that industry in particular is a slave to what is fashionable.
The "deep historical forces" you mention, I suspect, refers to the class struggle between rich and poor in the United States that dates back to at least the Gilded Age, and really to the revolutions both here and in France.
If you give me more specifics I can taylor this answer further to your needs.