The National Museum of American History opened to the public in January 1964 as the Museum of History and Technology. It was the sixth Smithsonian building on the National Mall in Washington, D.C. The Smithsonian was established in 1846 by an act of Congress as an institution for the "increase and diffusion of knowledge." By the 1850s the organization was called the U.S. National museum and housed in the first Smithsonian building. Smithsonian collections developed both as specimens and as historical and technological objects. In 1911, the Smithsonian completed the Natural History Building to store and exhibit the former items. On June 28, 1955, President Dwight D. Eisenhower signed the bill authorizing $36 million for a National Museum of History and Technology. Groundbreaking took place on august 22, 1958. During the five years of construction, staff members planned the inaugural exhibitions under the direction of Frank A. Taylor and John C. Ewers, the new museum's first director and assistant director. When the building opened in 1964, ten exhibitions halls were complete. The Museum's area is approximately 750,000 square feet, including a basement, three main exhibition levels, two office-collection levels, and a mechanical penthouse on the roof. The space includes workshops, laboratories, offices, libraries, archives, and other support areas along with an auditorium, a bookstore, gift shops, public and staff cafeterias, an ice cream parlor, and a working post office. The building's location on the national Mall qualifies it as a category | National Historic Landmark. In October 1980, the Museum's name was changed to the National Museum of American History to better represent its basic mission--the collection, care, and study of objects that reflect the experience of the American people.