The Thomas Jefferson Building is the oldest of the four United States Library of Congress buildings. Built between 1890 and 1897, it was originally known as the Library of Congress Building. It is now named for the 3rd U.S. president Thomas Jefferson, whose own book collection became part of the library in 1815. The building is located on First Street SE between Independence Avenue and East Capitol Street in Washington, D.C., across from the U.S. Capitol. The Beaux-Arts style building is known for its classicizing facade and elaborately decorated interior. The building's main architect was Paul J. Pelz, initially in partnership with John L. Smithmeyer, and succeeded by Edward Pearce Casey during the last few years of construction. The building was designated a National Historic Landmark in