The idea of a major library expansion took shape more than 40 years ago under the directorship of Warren Watson. With the passage of the Americans with Disabilities Act in the early 1990s, the City of Quincy began to explore ways to enlarge the Main Library and make it fully accessible.

As plans for a major building expansion progressed, the Library Board of Trustees recognized that private funds were needed to supplement the committed public money. The Trustees pledged the remaining assets of the Crane Trust Fund towards the expansion and in 1995 formed the Thomas Crane Public Library Foundation, Inc. as a 501(c)(3) non-profit organization charged with raising private funds for the building project.  

From 1995 to 2000, the Foundation raised nearly $1 million in private donations for the expansion, renovation and restoration project. The project was carried out in two phases: the first, the renovation of the 1938 Coletti addition and the construction of a 55,000 square foot new addition, was completed in February 2001. The second phase, restoration of the 1882 National Historic Landmark H. H. Richardson building and its 1907 Aiken wing, was completed in October 2001.

Upon completion of this initial project, the Foundation became inactive until 2014, when the Trustees recruited a new board of directors. Since then, the Foundation has raised private funding to support excellence and innovation in the facilities, services and programs of all branches of the Thomas Crane Public Library.