(Aug. 21–Oct. 7, 1944), meeting at Dumbarton Oaks, a mansion in Georgetown, Washington, D.C., where representatives of China, the Soviet Union (Union of Soviet Socialist Republics), the United States, and the United Kingdom formulated proposals for a world organization that became the basis for the United Nations.

This conference constituted the first important step taken to carry out paragraph 4 of the Moscow Declaration of 1943, which recognized the need for a postwar international organization to succeed the League of Nations. The Dumbarton Oaks proposals (Proposals for the Establishment of a General International Organization) did not furnish a complete blueprint for the United Nations. They failed to provide an agreed arrangement on such crucial questions as the voting system of the proposed Security Council and the membership provisions for the constituent republics of the Soviet Union. These issues were resolved at the Yalta Conference in February 1945, which also resulted in the proposal of a trusteeship system under the new agency to take the place of the League mandate system. The proposals, as thus supplemented, formed the basis of negotiations at the San Francisco Conference, out of which came the Charter of the United Nations in 1945.