it used part of a Sperry Gyroscope Company factory in Lake Success, New York, for most of its operations, including the Security Council, between 1946 and 1952. Between 1946 and 1950, the General Assembly met at the New York City Pavilion in Flushing Meadows, which had been built for the 1939 New York World's Fair (now the site of the Queens Museum). New York City Planning Commissioner Robert Moses convinced Nelson Rockefeller to purchase a piece of land along the East River in New York City from real estate developer William Zeckendorf Sr.; The purchase was funded by Nelson's father, John D. Rockefeller Jr. The Rockefeller family owned the Tudor City Apartments across First Avenue from the Zeckendorf site. The UN ultimately chose the New York City site over Philadelphia after Rockefeller offered to donate the land along the East River. The UN headquarters officially opened on January 9, 1951, although construction was not formally completed until October 9, 1952. Structure and associated organizations The basic constitutional makeup of the United Nations has changed little, though vastly increased membership has altered the functioning of some elements. The UN as a whole has generated a rich assortment of non-governmental organizations and special bodies over the years: some with a regional focus, some specific to the various peacekeeping missions, and others of global scope and importance. Other bodies (such as the International Labour Organization) formed prior to the establishment of the United Nations and only subsequently became associated with it. Milestones In October 2015, over 350 landmarks in 60 countries were lit in blue to commemorate the 70th anniversary of the world body. See also Diplomatic history of World War II Foreign policy of the Franklin D. Roosevelt administration#Founding the United Nations Foreign policy of the Harry S. Truman administration#United Nations Growth in United Nations membership List of members of the United Nations Security Council Timeline of UN peacekeeping missions List of UN Secretaries-General Reform of the United Nations List of vetoed United Nations Security Council resolutions by all countries United States and the United Nations Notes References Further reading Surveys Baehr, Peter R., and Leon Gordenker. The United Nations in the 1990s (St. Martin's Press, 1992) Bennett, A. LeRoy. Historical dictionary of the United Nations (1995) online Bosco, David L. Five to rule them all: the UN Security Council and the making of the modern world (Oxford UP, 2009) Fomerand, Jacques,