The biggest factor in the "Roaring 20s" was World War 1. While the war was going on, civilians at home were able to work in factories, manufacturing bullets, guns, uniforms, etc. The result was a well-employed populace, which meant that a great deal of money was being passed around, strengthening the economy. The same effect can be seen during World War 2, when wartime spending lifted the country out of the Great Depression. The end of the war meant that there was no more rationing, no more draft, and the soldiers were coming home, which was cause for everybody to celebrate. The combination of a victory in what was, at that time, the largest war ever waged, returning troops, a good economy, and no more wartime cutbacks meant that the general spirit of the country was extremely good.

Hopefully this is a good general overview of what contributed to the Roaring Twenties, and here are some sources on wartime factories and rationing.

Also the world had changed a lot in the years before the twenties. This time period (1877-1920) is commonly referred to as the progressive Era in America. Cities were growing at an insane rate leading America away from an agricultural Nation (Urbanization). Extraordinary men were also running our country in this time. Just look at every thing Roosevelt and Wilson did for us. Imagine watching the first planes take flight and seeing the first cars driving through such large never before seen cities. Like said above with the end of the Great War are economy was in and good place. People also felt invincible and were ready to have fun. It was a time period of breaking tradition and with the new and innovative technology of the day anything seemed possible! Sorry, this is my first post and I'm doing it from my phone.