Answer:
The US Senate, which is part of Congress, was supposed to ratify the Treaty of Versailles. It voted against it. It is one of its faculties, to ratify any treaty signed by the United States government. It also had to approve joining the League of Nations because becoming a member of an international organization requires signing a treaty of adhesion. In both accounts, president Wilson failed to persuade the Senate to vote in favor of the treaties mentioned above.
Step-by-step explanation: