<P> US President Franklin D. Roosevelt considered his most important legacy the creation of the United Nations, making a permanent organization out of the wartime Alliance of the same name . He provided continuous backstage political support inside the United States, and with Churchill and Stalin abroad . He made sure that leading Republicans were on board, especially Senators Arthur Vandenberg of Michigan, and Warren Austin of Vermont . He went public with strong advocacy in the 1944 presidential campaign, and turned detailed planning over to the State Department, where Sumner Welles and Secretary Cordell Hull worked on the project . The United States, Britain, Soviet Union and China made the major decisions and became permanent members of the all - powerful Security Council . Roosevelt made sure that each (including France) had a veto power, thus avoiding the fatal weakness of the League of Nations, which theoretically could order its members to act in defiance of their own parliaments . </P> <P> From August to October 1944, representatives of the Republic of China, Britain, the US and the USSR met to elaborate plans at the Dumbarton Oaks Conference in Washington, D.C. Those and later talks produced proposals outlining the purposes of the United Nations organization, its membership and organs, as well as arrangements to maintain international peace and security and international economic and social cooperation . Governments and private citizens worldwide discussed and debated these proposals . Winston Churchill urged Roosevelt to restore France to its status of a major Power after the liberation of Paris in August 1944 . </P> <P> At the Yalta Conference it was agreed that membership would be open to nations that had joined the Allies by 1 March 1945 . Brazil, Syria and a number of other countries qualified for membership by declarations of war on either Germany or Japan in the first three months of 1945--in some cases retroactively . </P> <P> On 25 April 1945, the United Nations Conference on International Organization began in San Francisco . In addition to Governments, a number of non-government organizations, including Rotary International and Lions Clubs International received invitations to assist in the drafting of a charter . After working for two months, the fifty nations represented at the conference signed the Charter of the United Nations on 26 June . Poland, which was unable to send a representative to the conference due to political instability, signed the charter on 15 October 1945 . The charter stated that before it would come into effect, it must be ratified by the Governments of the Republic of China, France, the USSR, the United Kingdom, and the United States, and by a majority of the other 46 signatories . This occurred on 24 October 1945, and the United Nations was officially formed . </P>

At which conference were the terms of membership created for the united nations