"<span>It improves trade between different parts of the world" is the best answer, since the joining of all the nations in the EU has been trade easier for a variety of countries. </span>
Stop fights between friday and sunday
Most Americans supported isolationism. They didn't want to engage in another European war. Although this agreement didn't include sending troops to Europe, it involved sending 50 destroyers to UK, so the amount of help was rather major.
Reign of Terror also known as the Great Fear (La Grande Peur), although it didn't start until September 1793. I couldn't find anything else to fit that time frame.