Delegates from 12 states including George Mason, Gouverneur Morris, Benjamin Franklin, and George Washington, met in Philadelphia on May 25, 1787 to discuss the problems between the states. Rhode Island did not attend because it did not want the national government to interfere with state rights. Washington was quickly elected president of the Constitutional Convention.

Many plans were presented at the Convention. James Madison wrote the Virginia Plan, which proposed that the central government be made up of a legislative branch, an executive branch, and a judicial branch. Roger Sherman proposed a plan to decide how many representatives should be sent to Congress from each state. This plan, which became known as the Great Compromise, established a Congress made of two separate houses: the House of Representatives and the Senate.

How the votes for President should be elected was another issue at the Convention. The delegates reached an agreement by creating the Electoral College, which gave each state as many votes as its number of senators and representatives in Congress. Slavery became an issue because each state's representation in the House of Representatives would be based on population. Northern states wanted to end slavery but most southern states did not. A compromise was reached where every five enslaved people would be counted as three citizens. On September 17, 1787, the Constitution of the United States was signed.