The United Nations replaced the League of Nations on 24 October 1945 after the 2nd World War. It was formed specifically to prevent another war like the 2nd World War. The Head of the United Nations is called the Secretary General.
The United Nations has its own postal agency. It originated in 1947 when the president of the United Nations General Assembly, a philatelist himself, came up with the idea. Their first stamps were issued in 1951 and there was intense interest from collectors at the time. The Postal agencies issues regularly sold out and sales increased. Interest slowed down after 1981 when the Postal Agency issued stamps showing support for the Palestinian people. When previously the agency was printing at least a million stamps for new issues, since then only about 400 000 copies per issue have been printed. The plus side to this is that the stamps are rarer and have become more valuable.
1951
Various Scenes Series
SG # 1
Unused (NH)
SG # 2
Unused (NH)
SG # 3
Unused (NH)
SG # 4
Unused (NH)
SG # 5
Unused (NH)
SG # 6
Unused (NH)
1961
Various Scenes Series
SG # 92
Used (Hinged)
1963
United Nations Temporary Executive Authority in New West Guinea Series
SG # 122
Used (Hinged)
1964
UN Trade & Development Conference in Geneva Series
SG # 130
Used (Hinged)