The Dumbarton Oaks Conference was held between August and October 1944. The principal objective of Dumbarton Oaks was to discuss the possibilities of creating an international organisation that would maintain world peace after the end of World War Two.
In fact, there was not one meeting at Dumbarton Oaks, but a series of meetings. These meetings were attended by representatives of the Soviet Union, Great Britain, the United States and China. The structure and form of a United Nations had to be discussed though the primary issue was the make-up of the Security Council and what its relationship would be to the League of Nations that was still in existence.
The main issue at stake was the use of the power of veto in the Security Council. This was to come to light at the Yalta meeting again and continued at the San Francisco conference of April to June 1945.