After the war, the Germans had to agree to the Treaty of Versailles. Germany had to pay approximately $31.5 billion in reparations. They also had to take responsibility for the war. Part of the treaty said the countries of the world should come together to make an international organization to stop wars from happening. This organization was called the League of Nations. The United States Senate did not agree with this, even though it was the idea of the US president, Woodrow Wilson. Woodrow Wilson tried to tell the American people that they should agree, but the United States never joined the League of Nations. Problems with the Treaty in Germany would later lead to the World War II.