Origins

The United Nations is the successor to the League of Nations, the international organization formed after World War I (1914-1918). The first commitment to establish a new international organization was made in the Atlantic Charter in 1941. The principles of the Atlantic Charter were more widely accepted in the Declaration by United Nations, signed on January 1, 1942, by representatives of 26 Allied nations that were fighting against the Axis powers during World War II. In a 1943 conference in Moscow, representatives of the Union of Soviet Socialist Republics (USSR), Britain, China, and the United States signed a declaration in which they recognized the need to establish a general international organization.

In the fall of 1944 representatives of the four powers met in Washington, D.C. to work out proposals for an international organization. They agreed on a draft charter that specified its purposes, structure, and methods of operation, but they could not agree on a method of voting in the proposed Security Council. The voting issue was settled at the Yalta Conference in the USSR in February 1945, when American president Franklin Delano Roosevelt, British prime minister Winston Churchill, and Soviet premier Joseph Stalin met for the last of their wartime conferences.

Delegates from 50 nations met in San Francisco later in 1945, for what was officially known as the United Nations Conference on International Organization. They completed and approved a charter consisting of 111 articles. The charter became effective on October 24, 1945, after ratification by a majority of the signatories.

In December 1945 the Congress of the United States invited the UN to establish its headquarters in the United States. In 1946 the UN moved to a temporary location in Lake Success, New York, and later that year purchased a site bordering the East River in New York City. The complex, completed in mid-1952, includes the General Assembly Hall, the Secretariat Building, the Conference Building, and the Dag Hammarskjцld Library.

Under the charter, UN membership is open to all peaceful states that accept the obligations of the organization. The 50 nations that attended the San Francisco conference, with the addition of Poland, became founding members of the United Nations. China initially was represented by a delegation from the Nationalist government on Taiwan, but in 1971 the General Assembly voted to seat the delegation from the People's Republic of China instead.

New members are admitted by a two-thirds vote of the General Assembly on the recommendation of the Security Council. Since 1945 membership has more than tripled, mainly with the admission of many new African and Asian countries that had been European colonies. As of 1995, the UN had 185 members.