1970 Berlin
1972 Berlin
1971 Berlin
1964 Berlin
1969 Berlin
1973 Berlin
1966 Berlin
1974 Berlin
1975 Berlin
1965 Berlin
Commemorative proof cards each feature a stamp from US #2991.
Fleetwood cover set celebrates 11th International Botanical Congress (1969).
For more than 75 years, the UN has worked toward international peace.