Library of Congress (Thomas Jefferson Building)

The Library of Congress is the research library that serves the United States Congress and is the de facto national library; it was established in 1800 and has grown into the largest library in the world by shelf space and number of items. The ornate Thomas Jefferson Building, which houses exhibitions and the Main Reading Room, opened in 1897 and features extensive architectural ornamentation and murals. The Library offers public exhibitions and guided tours of its historic spaces.