On March 10, 1902, the library became a tax-supported free public library, open to all residents of Portland. In 1903, services were extended to all residents of Multnomah County and the Multnomah County commissioners became ex officio members of the library board.
On July 1, 1990, after 126 years of guiding the library to the respected community position it currently enjoys, the Library Association of Portland transferred ownership of the library's buildings, books and other holdings to the people of Multnomah County, to be governed by the Multnomah County Board of Commissioners.
On November 6, 2012, voters approved formation of the Multnomah County Library District to fund library services. Library district funding took effect July 1, 2013.
Histories of neighborhood libraries
- Albina Library
- Belmont Library
- Capitol Hill Library
- Central Library
- Fairview-Columbia Library
- Gregory Heights Library
- Gresham Library
- Hillsdale Library
- Holgate Library
- Hollywood Library
- Kenton Library
- Midland Library
- North Portland Library
- Northwest Library
- Rockwood Library
- St. Johns Library
- Sellwood-Moreland Library
- Troutdale Library
- Woodstock Library