Congress spent $5,000 on its first library in 1800, and British troops burned every volume in 1814. Thomas Jefferson offered his own shelves as replacement — 6,487 books, sold in 1815 for $23,950. A fire in 1851 destroyed roughly two-thirds of that purchase. Yet the transaction set the institution's governing idea: no subject is foreign to a legislature. A Library of Congress Guided Tour still begins from that premise. The collections now exceed 170 million items, held on roughly 838 miles of shelving beneath Capitol Hill. The Thomas Jefferson Building opened on 1 November 1897, after a construction campaign authorised by Congress in 1886. John L. Smithmeyer and Paul J. Pelz drew the Italian Renaissance exterior; Edward Pearce Casey directed the interiors. More than forty American painters and sculptors were commissioned. The final cost came in under the congressional appropriation — an outcome noted, at the time, as unusual. Washington DC Library of Congress tour routes and Library of Congress Guided Tour tours have followed much the same sequence since: the bronze doors, the Great Hall, the Main Reading Room gallery. The Great Hall works as a manifesto in marble. Stained glass, mosaic, and inscription carry a single argument — that knowledge is public property. Elihu Vedder's Minerva mosaic stands on the stair landing, the goddess setting down her weapons to guard a scroll of learning. Above, the Main Reading Room rises 160 feet to a dome ringed by Edwin Blashfield's Evolution of Civilization, with 236 desks arranged in concentric rings below. Roland Hinton Perry's Neptune Fountain occupies the First Street facade. A gilded Torch of Learning tops the lantern. That density explains why a Library of Congress Guided Tour tour concentrates on the fabric of the building rather than the stacks, which remain closed to visitors. Today the Library functions as three things at once: the research arm of Congress, the United States Copyright Office, and a public museum. Its Coolidge Auditorium has hosted commissioned chamber music since 1925. The Treasures Gallery, opened in 2025, placed a Gutenberg Bible — one of three perfect vellum copies known — alongside rotating manuscripts and a reconstruction of Jefferson's library. Entry costs nothing; a timed-entry reservation is required. Among Capitol Hill landmarks, it remains the one built explicitly for readers, and a Library of Congress Guided Tour is how most visitors first learn to read it.