"Opened to the public as part of the country's bicentennial celebration in 1976, this is the largest of the Smithsonian Institution's 20 museums. It is the most-visited museum in the U.S. (and the second-most-visited museum in the world behind the Louvre), containing the world's largest collection of air and space craft, as well as interactive flight simulators, an IMAX theater, and the Einstein Planetarium. More than 60,000 objects connected with aviation and human flight are housed here, including the Wright brothers' 1903 Wright Flyer; Charles Lindbergh's Spirit of St. Louis ; Chuck Yeager's Bell X-1, the Glamorous Glennis , which broke the sound barrier; astronaut John Glenn's Friendship 7 Mercury capsule; the Apollo 11 command module Columbia , which carried the first men to the moon; the Apollo-Soyuz Hook-up; and Skylab. As immense as the museum may seem, you are looking at only 10 percent of the entire collection. The remaining 90 percent is located at the Steven Udvar-Hazy Center in Chantilly, Virginia, the largest air and space museum building in the world."