The Boston Public Library is the municipal public library system in Boston, Massachusetts, United States, founded in 1848. The Boston Public Library is also the Library for the Commonwealth (formerly library of last recourse) of the Commonwealth of Massachusetts; all adult residents of the commonwealth are entitled to borrowing and research privileges, and the library receives state funding. The Boston Public Library contains approximately 24 million volumes, and electronic resources, making it the third largest public library in the United States, behind the federal Library of Congress and the New York Public Library, which is also privately endowed. In fiscal year 2014, the library held more than 10,000 programs, all free to the public, and lent 3.7 million materials.
The library's central branch building, located facing Copley Square in the city's Back Bay neighborhood, was designated as a Boston Landmark by the Boston Landmarks Commission in 2000. Its oldest portion, designed by Charles Follen McKim and opened in 1895, is a National Historic Landmark for its outstanding Beaux-Arts architecture.