The Smithsonian Institution ( smith-SOH-nee-ən; or simply the Smithsonian) is a group of museums, education and research centers, created by the United States federal government "for the increase and diffusion of knowledge". Founded on August 10, 1846, it operates as a trust instrumentality and is not formally a part of any of the three branches of the federal government. The institution is named after its founding donor, British scientist James Smithson.