The Postal History Foundation, 920 N. First Ave., features stamps, postmarks and books tracing the history of the U.S. Postal Service and caters to serious philatelists and postal historians as well as casual collectors and youth education. Original equipment from the Naco post office as well as antique file cabinets and other memorabilia from Arizona post offices are on display.
An adjacent building houses a research library of philatelic literature and a collection of Civil War memorabilia, books and documents. A working post office is on-site.