Early in World War II, the representatives of nine European governments fled to London. Nazi Germany had conquered much of Europe and had driven these leaders from their homelands. Representatives of Britain and the Commonwealth nations met in London with leaders of Belgium, Czechoslovakia, France, Greece, Luxembourg, the Netherlands, Norway, Poland, and Yugoslavia. On June 12, 1941, all these nations signed a declaration pledging to work for a free world, where people could live in peace and security. This pledge, usually called the Inter-Allied Declaration, was the first step toward building the UN.

The Atlantic Charter followed the Inter-Allied Declaration by two months. It was signed by President Franklin D. Roosevelt of the United States and Prime Minister Winston Churchill of Britain. The Atlantic Charter expressed their hope for a world where all people could live free from fear and need. It also expressed their intention to seek eventual disarmament and economic cooperation.

On Jan. 1, 1942, representatives of 26 nations signed the Declaration by United Nations. This was the first official use of the words United Nations. The declaration approved the aims of the Atlantic Charter and was later signed by 21 other nations.

On Oct. 30, 1943, representatives of Britain, China, the Soviet Union, and the United States signed the Moscow Declaration on General Security. This declaration approved the idea of an international organization for preserving world peace. A month later, Roosevelt, Churchill, and Premier Joseph Stalin of the Soviet Union met at Teheran, Iran. The three men declared that they recognized the responsibility of all the United Nations to achieve lasting peace.

The Dumbarton Oaks Conference. From August to October 1944, representatives of Britain, China, the Soviet Union, and the United States held a series of meetings at the Dumbarton Oaks estate in Washington, D.C. The goal of these meetings was to plan a peacekeeping organization. The four nations succeeded in drawing up a basic plan, though they could not agree on some important questions. The plan's main feature was a Security Council on which Britain, China, France, the Soviet Union, and the United States would be permanently represented. The issue of voting rights and procedures within the Council remained unsettled, however.

In February 1945, Roosevelt, Churchill, and Stalin met at Yalta in the Crimea. At this meeting, they agreed that some minor actions of the Security Council could not be vetoed by the permanent members. The three leaders announced that a conference of United Nations would open in San Francisco on April 25, 1945. This conference would use the plan worked out at the Dumbarton Oaks Conference to help prepare a charter for the UN.

The San Francisco Conference. Delegates from 50 nations met in San Francisco for the United Nations Conference on International Organization. The conference opened on April 25, 1945, 13 days after the death of Roosevelt and 12 days before the surrender of Germany. Victory over Japan was still four months away.

At the conference, some major disagreements arose between the Big Three (Britain, the Soviet Union, and the United States) and the smaller, less powerful nations. The Big Three believed they could guarantee future peace only if they continued to cooperate as they had during the war. They insisted that the Charter of the United Nations should give them the power to veto actions of the Security Council. The smaller nations opposed the veto power but could not defeat it. They did succeed in adding to the importance of such UN organs as the General Assembly and the Economic and Social Council. In these bodies, responsibilities could be shared more equally than in the Security Council. Such efforts by smaller nations helped create an organization that had far-reaching powers and responsibilities.

On June 26, 1945, all 50 nations present at the conference voted to accept the charter. Poland had been unable to attend but later signed the charter as an original member. The charter then had to be approved by the governments of the five permanent members of the Security Council and of a majority of the other nations that signed it. It went into effect on Oct. 24, 1945, a date celebrated every year as United Nations Day.