The Smithsonian Institution was founded on this date (August 10th) in 1846. Named for British scientist James Smithson, who willed his fortune to the U.S. to establish the institution, today the Smithsonian is made up of 19 museums (including the National Air and Space Museum — the most visited museum in the U.S.), the National Zoo, and nine research centers. The Smithsonian houses more than 136 million items in its collections, earning it the nickname of “the nation’s attic.”