List of U.S. state libraries and archives

In the United States of America, sub-national governmental state library agencies established in each state have long been a catalyst for a great deal of the motivation for public library cooperation. This has been since the founding of the movement, starting in 1890 when Massachusetts created a state Board of Library Commissioners charged to help communities establish and improve public libraries.

Source: Wikipedia — List of U.S. state libraries and archives (CC BY-SA 4.0)