The New York Public Library (NYPL) is the third largest public library in North America and is one of the United States' most significant research libraries. It is simultaneously one of the largest public library systems in the United States and one of the largest research library systems in the world. It is a privately managed, nonprofit corporation with a public mission, operating with both private and public financing. The historian David McCullough has described the New York Public Library as one of the five most important libraries in the United States, the others being the Library of Congress, the Boston Public Library, and the university libraries of Harvard and Yale.
The New York Public Library has branches in the boroughs of Manhattan, The Bronx and Staten Island. According to the American Library Association, the branch libraries comprise the twenty-sixth largest library in the United States. New York City's other two boroughs, Brooklyn and Queens, are served by the Brooklyn Public Library and the Queens Borough Public Library respectively. These libraries predate the consolidation of New York City.
Currently, the New York Public Library consists of 87 libraries: four non-lending research libraries, four main lending libraries, a library for the blind and physically challenged, and 77 neighborhood branch libraries in the three boroughs served. All libraries in the NYPL system may be used free of charge by all visitors. As of 2008, the research collections contain 44,160,825 items (books, videotapes, maps, etc.) of which 15,985,192 are books. The Branch Libraries contain 7,565,579 items of which 4,416,812 are books. Together the collections total more than 50 million items, and the books number more than 20 million, a number surpassed only by the Library of Congress and the British Library.