- First Library Storytime, 1899, West End Branch
- First fully organized children's department, 1899, Main Library
- First Training Class for Children's Librarians, 1900, Main Library
- First Science and Technology Department, 1902, Main Library
- First "browsing room" in a large city library, 1938, Gillespie Room
- First Public Library/Private College partnership, 1997, Library Center
- Edwin H. Anderson, 1895-1904
- Anderson H. Hopkins, 1905-1908
- Harrison W. Craver, 1908-1917
- John Hopkins Leete, 1917-1928
- Ralph Munn, 1928-1964
- Keith Doms, 1964-1969
- Anthony A. Martin, 1969-1986
- Robert B. Croneberger, 1986-1998
- Herb Elish, 1999-2005
- Barbara K. Mistick, 2005 -
- Andrew Carnegie offered the City of Pittsburgh $1 million to build and equip the Main Library and five branches.
- Ground is broken for Main Library.
- Andrew Carnegie dedicates the Main Library.
- Lawrenceville Branch built
- West End Branch built
- Storytime is held at the West End Branch. Widely believed to be the first library storytime.
- Boys and Girls Room opens at the Main Library-the first fully organized children's Department
- Wylie Avenue Branch opened
- Mount Washington Branch built
- Hazelwood Branch built
- Training Class for Children's Librarians begins-first in the nation
- Science and Technology Department opens-the first in a public library
- Original East Liberty Branch built
- Service to the Blind begins
- Homewood was the eighth and last of the "Carnegie branches," and the last branch to be erected in Pittsburgh until 1964 when the City of Pittsburgh began its building program.
- Downtown Branch opened in the City-County Building
- Brookline and Carrick Branches open
- Downtown-Business Branch moved to the Union Trust Building
- Art Reference Division established
- Gillespie Room opens-the first browsing room in a public library
- Music Division established
- Knoxville Branch moved from Rochelle School to Brownsville Road
- Library Staff Association formed
- CLP celebrated its 50th birthday with an open house that attracted 3,000 visitors
- Books from the Science and Technology Department circulate to the public for the first time
- Business Branch was moved to the Frick Building
- Allegheny Regional and its Woods Run branch become part of the CLP system
- CLP begins lending materials free of charge to all residents of Allegheny County
- Business and Downtown Branches moved to the Kaufmann's Service Annex
- CLP designated as District Library Center and Resource Center by the Commonwealth of Pennsylvania
- Carnegie Library School (originally the Training Class for Children's Librarians) is moved to the University of Pittsburgh
- Current East Liberty Branch built
- Squirrel Hill Branch built
- Carnegie Library of Pittsburgh became the first public library outside of Ohio to access the OCLC database and to begin to catalog library materials electronically.
The Carnegie Institute and Library (Main) in Oakland was certified on March 30, 1979 as a landmark property by the National Register of Historic Places . Established under the National Historic Preservation Act of 1966, the national historic preservation program is a partnership between the Federal, State, Tribal and local governments; private organizations; and the public. The National Register of Historic Places is the Nation's official list of cultural resources worthy of preservation. The National Register is part of a national program to coordinate and support public and private efforts to identify, evaluate, and protect our historic and archeological resources.
- Hill District Branch moves to its current location
- ULISYS was installed as the library’s first electronic circulation system.
- Martin Luther King, Jr. Reading Center built
- Citywide Friends of the Carnegie Library of Pittsburgh organized
- Brookline Branch moves to its current location
- Carrick Branch moves to its current location
- Oliver Rare Book Room dedicated
- Foundation Center opens at Main Library
- Allegheny Regional Asset District becomes major funder of Library operations
- Board of Trustees expands to include 12 new term trustees
- In preparation for the celebration of the 100th anniversary of the Main Library, the Music and Art and the Social Sciences Departments were renovated. A separate room was established to house Music and Art audio-visual materials. Hallway and department murals were cleaned and fleur-de-lis murals covered in the early 1900's were reexposed. Department computer equipment provided the first public Internet access.
- Carnegie Library of Pittsburgh celebrates its Centennial
- Carnegie Library of Pittsburgh, the Allegheny County Library Association (ACLA) and the Commission on the Future of Libraries partnered to develop the Electronic Information Network (eiNetwork). The eiNetwork was launched in 1996 with capital investments from the Foundation community, Allegheny County, and ACLA.
- Main Library Children's Department is renovated
- Libraries Online!, a Gates Grant funded public computer lab, opened at the East Liberty Library
- Technology Learning Center, a Gates Grant funded public computer lab, opened at the Main Library
- Strategic Planning Process begins and four areas of focus are identified: service to youth, service to seniors, consumer health information, virtual reference
- A plan is created to begin to renovate library branches by diverting $1 million of operating funds into debt service on a $15 million bond issue.
- June: Carnegie Library of Pittsburgh received an Addy Award from the Pittsburgh Chapter of The American Advertising Federation for Annual Report, "The Book is Dead".
- June: Carnegie Library of Pittsburgh's Annual Report "The Book is Dead" is named Best of Show by the American Library Association.
- Capital Improvement Program begins. Programming and design work commences for Brookline, Homewood, Squirrel Hill and Woods Run libraries. Planning for the reorganization of the Main Library's first floor also begins.
- Statewide Virtual Reference program (PA Librarian Live) begins service. The program is a collaboration between CLP, Commonwealth Libraries, Free Library of Philadelphia and Pennsylvania State University. CLP serves as project manager.
- June 2002: Carnegie Library of Pittsburgh's Annual Report "Know Place" is named Best of Show by the American Library Association.
- November 2002:Carnegie Library of Pittsburgh received the AARP 2002 Excellence Award.
- February: West End Warehouse and Bookmobile Center, opened in 1966 to store older journals and serial titles, closes for renovations.
- March: Depository for Carnegie Library of Pittsburgh Historic collections established at the Allegheny Regional Library, combining collections previously housed at the Allegheny Regional Branch, the Main Library in Oakland and the West End Warehouse.
- Homewood temporarily closes for 6-8 months renovation
- Homewood library restored to its original grandeur officially reopens on Nov. 3, 2003
- Grand Re-Opening Celebration for Carnegie Library of Pittsburgh - Homewood, Nov. 22, 2003
- Brookline temporarily closes for renovations
- Grand Re-Opening Celebration for Carnegie Library of Pittsburgh - Brookline -- Feb. 7, 2004
- Staff of CLP-Hazelwood prepares for relocation to its new home on Second Avenue, the community’s main street. Thousands of books, CDs, movies and other collections are sorted, labeled and packaged in a matter of days before the professional movers take over. -- March 15, 2004
- CLP-Hazelwood hosts a grand opening celebration for the community in its new location -- May 1, 2004
- August 6, 2004 marked the closing of the Library Center on Wood Street and an end of the joint operating agreement of the library with Point Park College. Renovations for the new location of the Downtown and Business Library began immediately.
- September: The Library Support Center was opened after a one year renovation. Designed by Hammer-Mann Designwerks, the building that housed the former Bookmobile Center and Warehouse in the West End of Pittsburgh was transformed into Carnegie Library of Pittsburgh’s Technical Services Department which was relocated from Oakand. The Mobile Library Services of the Allegheny County Library Association is a tenant of this facility.
- September: Pennsylvania Library Association honored Carnegie Library for the Blind and Physically Handicapped (LBPH) with the Marietta Y. King and Alberta Walden Still Diversity Award.
- Squirrel Hill temporarily closes for renovations
- October 3, 2004, a ribbon-cutting ceremony and community day celebration was held to dedicate the newly renovated First Floor of the Main Library in Oakland. Improvements, designed by Edge Studio, include a vibrant Teens area, new multimedia informational displays, an indoor and outdoor reading deck, a new Library Shop and a café.
- On February 1, the new location for Carnegie Library of Pittsburgh - Downtown & Business at 612 Smithfield Street was open for business. The library was designed by Burt Hill Kosar Rittelmann Associates
- April 19, 2005 - Carnegie Library of Pittsburgh – Squirrel Hill reopened after a renovation designed by Arthur Lubetz Associates Architects. Key features of the renovation include a 7,000 square foot expansion to accommodate expanded collections, a new teen area, the Namm Business Center and a larger children's area. The new library includes a prominent glass enclosed entrance along Forbes Avenue, a new passenger elevator, upgraded public meeting rooms, and a drive-up book drop in the parking garage for added customer convenience.
- Carnegie Library of Pittsburgh – Woods Run is the next library that will be renovated as part of the library’s Capital Improvement Program. Dates for the renovation, which is being designed by Loysen + Kreuthmeier, will be announced in early summer, 2005.
- April 2005: Carnegie Library of Pittsburgh - Downtown & Business recognized among Pittsburgh's "Coolest Spaces" by Cool Space Locator.
- June 2005: Carnegie Library of Pittsburgh - Brookline named "Library Building of the Year" by the American Institute of Architects and the American Library Association.
- October 2005: Carnegie Library for the Blind and Physically Handicapped (LBPH) received a Verizon Foundation grant to provide Library customers with accessible digital audiobook players in a trial study.
- October 2005: This year marks 100 years of Carnegie Library of Pittsburgh – East Liberty’s dedication to the community. In commemoration, the Library hosted a Centennial Celebration on October 8th.
- November 2005: Bestselling mystery author James Patterson and The Time Warner Book Group selected Carnegie Library of Pittsburgh as a James Patterson PageTurner Award national recipient. The Library was awarded a monetary grant for its annual Summer Reading Extravaganza.
- December 2005: Without fanfare, Carnegie Library of Pittsburgh - Main celebrated its 110 birthday on Saturday, November 5th. The Oakland facility opened in 1895 and was dedicated to provide to the citizens of Pittsburgh "a carefully selected, well rounded, constantly growing collection of books."
- December 7, 2005: Carnegie Library of Pittsburgh – Woods Run began a $2 million renovation project. Construction is expected to take up to six months, with an anticipated early Summer 2006 reopening.
- February 2006: Free, public wireless access was added to neighborhood locations
- February 2006: Carnegie Library of Pittsburgh announced plans to build a new branch location in the Hill District, making it the first new building in the city's library system since the Sheraden branch in 1980. To complete the move, the Library consolidated its two Hill District locations, closing the Martin Luther King Jr. Reading/Cultural Center.
- March 2006: More than 1,700 titles of digital audio books were added to the collection.
- March 2006: The U.S. National Commission on Libraries and Information Science (NCLIS) announces that Carnegie Library of Pittsburgh is the 2006 Pennsylvania state winner of the NCLIS Health Information Awards for Libraries for the Mental Health & Wellness series.
- April 2006: CLP - Allegheny Regional was severely damaged when a lightning strike hit the building's 115-year-old clock tower on April 7.
- May 2006: A study examining the Library's value to the local economy and its impact on the public confirmed that Carnegie Library of Pittsburgh is the region's most visited asset.
- June 2006: Pennsylvania Governor Ed Rendell pledges $7.5 million to the Library's Capital Campaign "Libraries for Life: Building Communities, Enriching Lives", kicking off the public phase of the initiative.
- August 6, 2006: CLP - Woods Run completed a lengthy $2 million renovation. Architect Karen Loysen of Loysen + Kreuthmeier transformed the library's exterior by replacing the building's brick walls with large windows that infuse the library with sunlight. Designated Teen and Children's areas, an interior design that showcases a centralized Customer Service area, and the first drive-through book drop in CLP's system are other integral design features.
- Sept 2006: The Carnegie Library in Pittsburgh won for its "Interactive UX" (User Experience) in the "Best Under $1 million" category at the 2006 ARCHI-TECH AV Awards.
- April 2007: Carnegie Library of Pittsburgh begins construction on the city's newest library. Officials broke ground on a new $3.15 million facility in the Hill District.