How did the US move from economic collapse to economic supremacy?
The US did this through preparing for World War II and through the aftermath of that war.
The Great Depression ended as the US started to get ready to fight in WWII. This increased production and it pulled men into the military, reducing unemployment dramatically. After the war ended, the US was supreme in the world's economy. This was because the US was the only major economy in the world which had not been devastated by the war. Bombing and other fighting had harmed Japan, Germany, France, and England terribly, leaving the US much wealthier than any other economy in the world.