History of the United Nations $8.5 million donation from John D. Rockefeller, Jr. The UN headquarters officially opened on January 9, 1951, although construction was not formally completed until October 9, 1952. Under special agreement with the United States, the UN enjoys certain diplomatic privileges and immunities, but generally the laws of New York City, New York State, and the United States apply. While the principal headquarters of the UN remain in New York City, major agencies base themselves in Geneva, The Hague, Vienna, Nairobi and elsewhere. The basic constitutional makeup of the United Nations has changed little, though vastly increased membership has altered the
Headquarters of the United Nations as well as a deck over FDR Drive on the headquarters' eastern side. To fit in with the accelerated schedule of construction, the steel would have to be delivered by September. The project also included a four-lane, $2.28 million vehicular tunnel under First Avenue so that traffic could bypass the headquarters when the UN was in session. The tunnel started construction on August 1, 1949. The tunnel involved two years of planning due to its complexity. Property inside Tudor City, just west of the headquarters, was also acquired so that two streets near the UN headquarters could be widened. The