If the United Nations does not attempt to chart a course for the world's people in the first decades of the new millennium, who will? Kofi Annan
The United Nations officially came into existence on 24 October 1945, when the UN Charter had been ratified by a majority of the original 51 Member States. The day is now celebrated each year around the world as United Nations Day.
The purpose of the United Nations is to bring all nations of the world together to work for peace and development, based on the principles of justice, human dignity and the well-being of all people. It affords the opportunity for countries to balance global interdependence and national interests when addressing international problems.
There are currently 192 Members of the United Nations. They meet in the General Assembly, which is the closest thing to a world parliament. Each country, large or small, rich or poor, has a single vote, however, none of the decisions taken by the Assembly are binding. Nevertheless, the Assembly's decisions become resolutions that carry the weight of world governmental opinion.
The United Nations Headquarters is in New York City but the land and buildings are international territory. The United Nations has its own flag, its own post office and its own postage stamps. Six official languages are used at the United Nations - Arabic, Chinese, English, French, Russian and Spanish. The UN European Headquarters is in the Palais des Nations, Geneva, Switzerland. It has offices in Vienna, Austria and Economic Commissions in Addis Ababa in Ethiopia, Amman in Jordan, Bangkok in Thailand and Santiago in Chile. The senior officer of the United Nations Secretariat is the Secretary-General.
Even as the Second World War raged, the leaders of Britain, China, the US and the USSR, under intense pressure from the press and public, discussed the details of a post-war organization. In 1944 representatives of China, the UK, the US and the USSR meeting at Dumbarton Oaks in Washington, DC, prepared a blueprint for an international organization. Towards the end of the war representatives of 50 countries gathered in San Francisco between April and June 1945 to hammer out the final text that would lay the foundations of international cooperation. This was the Charter of the United Nations, signed on 26 June by 50 countries. Poland, the 51st country, was not able to send a representative to the San Francisco conference but is considered an original member.

Information Provided by: The United Nations: An Introduction for Students (UN Cyber School Bus)