The Philadelphia City Institute was founded on March 15, 1852 by The Young Man's Institute (an organization for disadvantaged young men) as a "Literary Institute," modeled on the concept of Mechanics Institutes in Great Britain, which offered school facilities and a library.
PCI opened its doors at the northeast corner of 18th and Chestnut Streets in 1855. In 1857, females were granted the privilege of attending lectures, and later, the use of the library. The Institute provided lectures, concerts, free night school, and even drill practice during the Civil War. It was listed as a tourist attraction for those attending the Centennial Exhibition in 1876.
In 1923, the Institute moved across the street to a former residence at 218 S. 19th Street (West Rittenhouse Square), where it expanded services to children. In 1944, the Institute joined the Free Library of Philadelphia as a branch. The PCI Board of Managers agreed to provide the money to maintain the physical location, collection and programming.
The Philadelphia City Institute opened at its present quarters on May 11, 1957. It is located in the first floor and basement of a high-rise apartment building at 1905 Locust Street, which is partly situated on the former site of PCI. The library was designed by PCI board member Erling H. Pedersen. It was renovated in 1998 as part of the "Changing Lives" campaign, which brought Internet service to every branch.
A prominent mural by noted Philadelphia artist David McShane greets visitors at the entrance of the library. Commissioned by the Friends of PCI in 2000, the mural speaks to the history and mission of the branch, and the diversity of the community it serves.