It sent their economies into further decline--European countries had invested in our stock market and they relied on our financial assistance following the war.
Germany was relying on circular loans from the US which provided funds to help them pay for reparations. After the stock market crash, we were no longer able to aid which stopped money from flowing into Europe. This caused further decline in Europe preventing them from investing in their own countries let along buy goods from the US.
The answer in the space provided is Fontelle. It is the work
of Fontelle that had provided connections between enlightenment and science as
his work was able to link of the two and to properly provide a better
understanding of how it was connected.