The AOC (Articles of Confederation) really limited the power of Congress. They could not...
• Collect Taxes • Conduct foreign policy • Could not enforce laws
There were many other problems with the AOC as well. A huge one was that it was practically impossible to amend; all 13 states needed to unanimously agree on a change. Given the rivalry between the States, and the fact that Rhode Island hardly showed up for anything, it would be impossible to fix the AOC.
Congress also could not pay off the national debt. The US owed a whole lot of money after fighting the war. However, due to the fact that Congress couldn’t collect taxes, the government had to print more money which caused massive problems with the economy.