100 Match Factory Place, Bellefonte, Pennsylvania 16823, United States
APS is the world's largest organization for stamp collectors.
PO Box 1570, Parker, Colorado 80134, United States
Founded in 1955, the Liberian Philatelic Society works to promote the collecting, study and preservation of Liberian stamps and postal history.
27 Fairfield Lane, Capon Bridge, West Virginia 26711, United States
United States Possessions Society (USPPS)
7203 St Johns Way, University Park, Florida 34201, United States
2658 Iron Works Drive, Buford, Georgia 30519, United States
PO Box 16213, St. Paul, Minnesota 55116, United States
Scandinavian Collectors Club
PO Box 10552, Pittsburgh, Pennsylvania 15235-0552, United States
1401 Linmar Dr. NE, Cedar Rapids, Iowa 52402, United States
5881 West 75th St., Los Angeles, California 90045-1706, United States
PO Box 6634, Katy, Texas 77491-6634, United States
United States Stamp Society (TX)