The National Philatelic Collection is a collection of nearly six million postage stamps, revenue stamps, and related items, owned by the United States Government and managed by the Smithsonian Institution. It is housed within the National Postal Museum and a portion of the collection is on display in the museum's National Stamp Salon. The National Philatelic Collection is among the world's largest and most valuable stamp collections and, along with the Postmaster General's Philatelic Collection, is one of two stamp collections owned by the United States.