During World War 1 Americans desired to “make the world safe and peaceful for democracy”. President Wilson ordered  America’s military resources and  soldiers into war in 1917 to support the allies in Germany’s defeat.
Wilson’s plan for world peace was introduce before the war was over.  this plan known as the  “Fourteen Points” included a proposal for the  international League of  Nations. The United States did not join the League of Nations because the Senate failed to approve the Treaty of Versailles in 1919 . Many Americans still wanted to be isolationists.  A debate over the League of Nations occurred in United States Senate.  Protests to the U.S. joining the League of Nations focused on the fact that U.S. foreign policy decisions would be made by an international organization.
For more info… http://www.u-s-history.com/pages/h1324.html

This image above shows a small hen standing on this large egg.  The hen is President Wilson and the egg is the League of Nations. It is the demonstration of how Wilson is struggling to do everything by himself without the help of Congress.  If Congress ratified the Treaty of Versailleshe then  the hen would be bigger and the egg will be smaller and ready to hatch.

I Wonder Why Wilson’s 14 points for achieving a lasting peace in Europe was not accepted by the United States Congress?

I believe because Americans wanted to concentrate on only business and wealth and  not get overly committed into any international union with anyone.  I think many people thought that “entangling alliances” would be a cause for another war.