Allied countries eventually agreed on a peace treaty. It came to be known as the Treaty of Versailles. What were the major provisions of the Treaty of Versailles (what new institution did it establish? what restrictions did it set on militaries? who was assigned guilt for the war?)?

The Treaty of Versailles was negotiated by the powers of the Triple Entente and their allies at the Paris Peace Conference in 1919 in the Palace of Versailles until May 1919. With the signing of the peace treaty, the First World War ended at the level of international law. It was also the founding act of the League of Nations.  

As early as November 11, 1918, the Compiegne armistice ended the fighting of the First World War, but not the state of war. The German delegation was not allowed to take part in the negotiations, but was only able to obtain a few improvements to the content of the treaty by written submissions. The treaty stated that Germany and its allies were solely responsible for the outbreak of the world war and committed it to cession of territories, disarmament and reparation payments to the victorious powers. After the ultimate request, Germany signed the trety on June 28, 1919. After ratification and exchange of documents, it came into force on January 10, 1920. Because of its harsh conditions and the way it came about, the majority of Germans perceived the contract as an illegitimate and humiliating dictation.  

The United States Congress refused to ratify the Versailles Treaty in 1920. Therefore, the United States did not join the League of Nations and concluded a special peace with Germany in 1921, the Berlin Treaty.

no one really purchased it themselves, it was all america, they had debates etc.