Update: Since this article was written in 2012, the library building has been taken over by the Children’s Museum. Its future now seems assured.
Andrew Carnegie gave this library to the city of Allegheny, where it was built at the main intersection of the city in 1889. By some standards this was America’s first public library. Carnegie had given Braddock a library earlier (that library, in spite of the collapse of the town around it, still stands), and other philanthropists had given libraries to the public, like Enoch Pratt’s in Baltimore. But those were run as private charities with money from an endowment given by the philanthropist. Allegheny’s was built by Carnegie, but run by the city government.
In the 1960s, the library and its neighboring music hall were among the very few buildings spared when the rest of central Allegheny was demolished to make way for an ambitious urban-fantasy project called Allegheny Center. The redevelopment was not very successful, and today the concrete plazas that replaced downtown Allegheny are unnaturally quiet in the middle of the day. After the building was damaged in a lightning strike a few years ago, the library itself moved to a new building a few blocks up Federal Street. The music hall is still active as a theater, and there are a few offices in the library building, but this grand entrance is no longer in use.
Allegheny Center is a short walk from the North Side subway station.