For almost 100 years since the creation of the United States General Post Office, the exchange of mail between the United States and foreign countries was done through the execution of treaties between the United States and those countries. This piece-meal approach resulted in a series of postal rates and routes that made the preparation of the mails and identifying the correct postal rates a complex chore for citizens and postmasters alike.

Much of this complexity was eliminated in 1874, when many countries came together at Berne, Switzerland, and formed the General Postal Union. The goal was to create a set of common rates for the exchange of mails between the member countries, and a second set of rates between member countries and non-member countries. The General Postal Union was renamed as the Universal Postal Union in the following year. The new Universal Postal Union held regular conventions where they met and redefined the procedures to be used in this exchange of mail between countries. The result of these meetings was a treaty which either modified or replaced the previous treaties that governed the handling of mail.

The United States was an original member of the General Postal Union and has continued to participate into the present. Because of their international nature, the original treaties were prepared and published in French, and when later published in the United States, the original French was accompanied with an English translation. These treaties were typically published in the annual volumes of the Revised Statutes of the United States, which are difficult for most researchers to locate, and when located, cumbersome to navigate to find the few pages relevant to the Treaties.

The present Stamp Smarter Library bookshelf includes all of the UPU treaties ratified in the 19th century, with each as a stand-alone document. There is also a Portal that can be used to assist the researcher to locate the treaties ratified during the 20th century.

Our thanks to Ken Lawrence for his research in locating these treaties in the various editions of the Revised Statutes.