By the 1940s, the need for a new Downtown Library to replace the Carnegie-funded structure on Huron Street and State Street had become apparent. Years of study led to the selection of the site at the corner of South Fifth Avenue and William Street for this new library, which opened it doors on October 13, 1957. By the early 1970s this building itself had become insufficient to meet the needs of a growing library system (which by then had also constructed the Loving Branch, precursor to the Malletts Creek Branch). An expansion doubling the size of the 1957 building was completed in 1974. A third addition was completed in 1991, adding the 3rd and 4th floors and again doubling the size of the library, in order to meet the needs of a growing collection size, rising circulation numbers, and increased programming offerings.
In 2007, AADL hired PROVIDENCE Associates LLC to undertake a study assessing the 20-year feasibility of the Downtown Library. This study included 10 focus groups with more than 100 users of the AADL and sought to determine the needs of the library as its needs and offerings to the community continue to grow. The findings of this study led the AADL Board to issue a Request for Qualifications for Architectural and Engineering Services that eventually resulted in the selection of Luckenbach-Ziegelman Architects, PLLC of Ann Arbor. Skanska was hired as the construction firm who would undertake the project in whatever form it would eventually take.
At the same time as the development of the concept for the Downtown Library, the Ann Arbor Downtown Development Authority created a plan to replace the parking lot on the north side of the Library with an underground parking garage. This led the two organizations to develop a joint survey asking for feedback on both the Downtown Library and parking. The results of this survey will help guide the AADL and Lukenbach-Ziegelman Architects as plans for the Downtown Library develop.
In November 2008, the Library Board voted to suspend the Downtown Library Project as a result of the economic downturn.
In 2012, a Bond Election was held to fund demolition, temporary space, and construction of a new Downtown Library on the current site. With 84,084 ballots cast, the Bond Proposal failed 33,613 for to 41,363 against, with 9,108 ballots voting neither Yes nor No on the Library Bond question.
In 2017, the Library Board commissioned Reserve Advisors to develop a Full Reserve Study for the Downtown Library, to estimate the costs associated with continuing to operate and maintain the current Downtown Library building.
In 2018, the Library Board commissioned HBM Architects to develop a Building Program for a hypothetical new Downtown Library as a basis for further analysis.
In 2019, the Library Board commissioned the Bonner Advisory Group to produce a Feasibility Study investigating several potential redevelopment scenarios for a new Downtown Library as part of a mixed-use building.