The National Library of the United States of America is officially known as the Library of Congress. It is the national library of the United States and is located in Washington, D.C. The Library of Congress is the largest library in the world, with a collection of over 160 million items, including books, manuscripts, maps, photographs, and other materials. The library is an important cultural and educational institution in the United States and is a major research and learning resource for scholars, students, and the general public. The Library of Congress is open to the public and offers a variety of services, including research assistance, reference assistance, and the loan of materials.