The Universal Postal Union
Heinrich von Stephan (1831–1897), who had already founded the North German Confederation in 1868, encompassed the postal administration of several German states (Bergedorf, Bremen, Brunswick, Hamburg, Hanover, Lübeck, Mecklenburg-Schwerin and Mecklenburg-Strelitz, Oldenburg and Prussia, Schleswig-Holstein, Thurn & Taxis, and Saxony). In 1871, this Confederation became redundant with the formation of the German Imperial Post. Von Stephan focused on a new challenge: the formation of a Universal Postal Union.
On September 15, 1874, an international conference was held in Bern, Switzerland, at the initiative of Heinrich von Stephan. The conference was attended by 22 countries. As a result, a treaty was drafted and ratified by most participating countries as the Treaty of Bern. This treaty regulated the establishment of the Universal Postal Union, as it was called at the time. On October 9, 1874, the Union became a reality. Later, the name was changed to Universal Postal Union (Union Postale Universelle, UPU). The Netherlands signed the agreement on July 1, 1875. Many countries have honored Heinrich von Stephan with a postage stamp. On October 4, 1909, a monument made of bronze and granite was unveiled to commemorate the founding of the Universal Postal Union. The monument was designed by the French sculptor René de Saint-Marceaux, a member of the Paris Academy of Fine Arts. He was the winner of an international competition organized by the Swiss government.
The theme was: Around the World. The artist has grouped five messengers around the globe passing letters to each other. The five figures represent the five continents.
The silhouette of the monument was further developed as a logo for the UPU and first presented in 1951 on the UPU's magazine, Union Postale. The logo was adopted by all members of the UPU in 1967.
The founding countries were Belgium, Denmark, Germany, Egypt, Greece, Great Britain, Hungary, Italy, Luxembourg, the Netherlands, Norway, Austria, Portugal, Romania, Russia, Serbia, Spain, Turkey, the United States, Sweden, and Switzerland.
They became members on July 1, 1875. France became a member on January 1, 1876. In 1947, the Universal Postal Union became part of the United Nations. Currently, the Universal Postal Union has 191 participating countries. The last country to join was the Republic of Montenegro on July 26, 2006. Who will follow?

Cees, as always, a good story that philatelists can work with.
Great information for us. I would just like to point out that list of 191 countries:
http://www.upu.int/members/en/members.html