The Smithsonian is the largest collection of museums and research facilities in the world. It owes its existence to the bequest of the wealthy Englishman James Smithson. He left his substantial estate to the United States to be used for, "the increase and diffusion of knowledge." To this day, no one knows why he did this. From the perspective of its vision: "shaping the future by preserving our heritage, discovering new knowledge, and sharing our resources with the world," this talk presents the Smithsonian's history and includes a sampling of its greatest treasures.