The League of Nations was the first worldwide intergovernmental organisation whose principal mission was to maintain world peace. It was founded on 10 January 1920 by the Paris Peace Conference that ended the First World War. Its Covenant is the first chapter of the Treaty of St Germain, although most versions replace it with a note that it can be found in the Treaty of Versailles. Although the USA's Plenipotentiary had signed the Treaty of St Germain, the USA Senate refused to ratify it because of opposition to joining the League of Nations whose provisions for mutual support might embroil American troops in a foreign war not of their choosing. Instead, a separate peace treaty between the United States and Austria was signed in Vienna on August 24, 1921, and ratified in Vienna on November 8, 1921, becoming effective on the same day. Austria joined the League on 16 December 1920. The main organization became inactive when WWII began, and ceased operations on 20 April 1946. The full text of the Covenant is rather elusive! It can be read here.