On the occasion of the 150th anniversary of the founding of the United States Nautical Almanac Office, the U.S. Naval Observatory hosted a three-day Symposium and associated activities beginning March 3, 1999. The choice of date was in itself an historical exercise, and March 3, marking the passage of legislation appropriating funds for an American almanac, was the first of several dates that might have been chosen. The Nautical Almanac Office actually came into existence when the funds became available July 1, 1849, and the first Superintendent of the office was appointed July 11. Work commenced still later that year, and the first volume was published in 1852. Still, March 3, when the Congressional appropriation set all these events in motion, it's traditionally observed as our anniversary date. The details of this history can be found within this volume of Proceedings. The Nautical Almanac Office was established as an independent entity, and became part of the older Naval Observatory only a half century later. Part of the rationale for establishing an American office was to remove dependence upon foreign almanacs, especially the British Almanac, and to join the ranks of the few major powers producing almanacs at the time: Britain, France, Germany, and Spain. Somewhat over a century later, the almanac offices of the United Kingdom and the United States became equal partners co-producing these major publications. Thus, it was symbolically appropriate that the Symposium and a banquet were held at the British Embassy, next door to the Naval Observatory. Attending the event were representatives from the almanac offices of the United Kingdom, France, Spain, and Japan, and greetings were sent from Russia.