One of the areas in which United States philately differs from nearly all the rest of the world is in our Official Stamps. As an agency of the federal government (one of the powers our Constitution expressly designated as a federal power was control of the national post office) the US post Office always carried official mail for free. Congressmen and Senators had the Free frank and differing government agencies sent their mail for free often under the “penalty envelope” system which were preprinted to discourage private use by government workers. In 1873 the Post Office issued a series of stamps for the various government agencies that used stamps. A distinctive set was issued for each department that would use them and also to collectors who wished to purchase them. There are over 125 varieties of these issues of 1873 recognized as major numbers by the Scott catalog and nearly all of them are scarce. It is important to remember how unusual Official stamps are in the world of philately. Germany issued only a very few nineteenth century Official stamps. France, Russia, China, the Netherlands and in fact the vast majority of stamp issuing entities issued no Official stamps in the early period (and very few have issued any today). Further, of the few countries that did issue a quantity of different early Official issues (for example Great Britain, South Australia, New Zealand, Argentina, and Luxembourg), the United States was the only country that issued specially designed and engraved stamps for Official purposes and did not just overprint “Official” on existing postage stamps. It was this care and seriousness of purpose that have made US Officials so popular. They are beautiful stamps and have a wide specialty following.