Question

Why was the U.S. economy so important to the world economy in the 1920s?

Answer 1

WWI had ravaged the European economy

Explanation:

After WWI the USA became the creditors of the world and first of all in Europe. The economic growth was unprecedented and the Federal Reserve system created in 1913 enabled the USA to reach such a hegemony. Germany had been the First industrial power before WWI and in the twenties the USA overtook them in industrial production and economic prosperity.

The rebuilding of Europe was financed mostly with American capital, and Germany had a tremendous amount of American capital in its economy. It therefore explains why the 1929 crisis affected Germany so violently.