The United Nations (UN) is an intergovernmental organization formed to promote international cooperation. A replacement for the ineffective League of Nations, the organization was established after World War II in order to prevent another such conflict. At its founding, the UN had 51 member states; there are now 193. Headquarters of the UN is in Manhattan, New York City. The organization is financed by assessed and voluntary contributions from its member states. Its objectives include maintaining international peace and security, promoting human rights, fostering social and economic development, protecting the environment, and providing humanitarian aid in cases of famine, natural disaster and armed conflict.
The U.N. opened its headquarters in New York City this date in 1952. Although it is situated in New York City, the land occupied by the United Nations Headquarters and the spaces of buildings that it rents are under the sole administration of the United Nations and not the U.S. government. They are technically extra-territorial through a treaty agreement with the U.S. government. However, in exchange for local police, fire protection and other services, the United Nations agrees to acknowledge most local, state, and federal laws. (from Wikipedia)