The United States tried to stay out of World War 1 for several reasons. First, the United States had a policy of isolationism, which meant that it did not want to get involved in European affairs. Second, the United States was not ready to go to war. It had just come out of a civil war, and its army was not as large or well-trained as the European armies. Finally, the United States did not want to get involved in a war that was not in its interests. However, America finally entered the war for several reasons. First, Germany began sinking American ships, and American lives were being lost. Second, Germany began sending submarines into American waters, and this was a threat to American security. Finally, the United States felt that it had a duty to help the Allies, who were fighting against Germany.
The United States Senate rejected the Treaty of Versailles for several reasons. First, the Senate felt that the treaty was too harsh on Germany. Second, the Senate did not want to join the League of Nations, which was created by the treaty. Finally, the Senate was concerned about the possibility of future wars, and it did not want the United States to be bound by the treaty.