On August 10, 1846, President James K. Polk signed into law the act establishing the Smithsonian Institution. The entity is named for James Smithson, a rich and somewhat obscure British scientist, who left his entire estate and fortune to the United States for an establishment "for the increase and diffusion of knowledge."
Smithson died in Italy in 1829. His will stated that if his nephew didn't have an heir that the estate would go to the United States, even though Smithson had never even visited the country. The nephew was childless, and the U.S. inherited Smithson's estate.
Today's Smithsonian has 19 museums and galleries, including the recently announced National Museum of African American History and Culture. It also encompasses nine research facilities throughout the United States and the world, as well as the national zoo.