Justin Winsor was an American writer, librarian, and historian. His historical work had strong bibliographical and cartographical elements. He was an authority on the early history of North America and was elected the first president of the American Library Association as well as the third president of the American Historical Association.

The American Library Association (ALA) is a nonprofit organization based in the United States that promotes libraries and library education internationally. It is the oldest and largest library association in the world.