For almost two decades after its reorganization in 1769, the American Philosophical Society had no home of its own. Meetings were held at Carpenters Hall, the College of Philadelphia, Christ Church School, and occasionally at the home of Benjamin Franklin, while the issue of obtaining a site for a permanent home was debated. Although the Society was still recovering from the turmoil of the Revolutionary years, in 1783 the members decided that the time had finally come to construct their own building. The first property considered, a lot on Fifth Street near Arch owned by Francis Hopkins, was passed over when the option to obtain a lot in the State House Yard (now Independence Square) was presented. On March 28, 1785, the Pennsylvania Assembly voted to give this lot to the Society, and the torturous story of Philosophical Hall began.

Philosophical HallImmediately after obtaining this lot, the Society proceeded to excavate the cellar and foundations for their new building. Unfortunately, construction began before funding had been secured, and it would take four years before Philosophical Hall would be completed. Oversight of the construction was given to a committee of members lead by Samuel Vaughan, but after an initial call for subscriptions from the membership fell short of the mark, the project was plagued by a constant shortage of funds and significant delays. Limited finances influenced the construction of the building, as grandiose plans for its design were pared down to meet available resources. Eventually a loan from Benjamin Franklin saw the project to completion, and Philosophical Hall was opened for its first meeting on November 20, 1789.

Oblique view of Philosophical Hall, from Fifth StreetAs the home of the APS, Philosophical Hall provided a location for the Society's meetings, as well as for its growing library and collection of artifacts. However even before the Hall was completed, the membership elected to raise funds by renting out the unused space, and for the next 145 years, the Society shared its building with a succession of tenants. The first person to rent space in Philosophical Hall was John Vaughan, librarian for the Society and wine merchant, who rented cellar space to store wines and liquors. Late, a number of distinguished institutions rented space in the Hall, including the University of Pennsylvania, which held classes in the unused rooms, from 1789-1794, and the College of Physicians of Philadelphia, which held meetings in the Hall every Wednesday evening and on special occasions, most notably during the 1793 Yellow Fever epidemic. Perhaps the best known of all the tenants was Charles Willson Peale's Philadelphia Museum which was located in Philosophical Hall from 1794 to 1811. After Peale relocated to Independence Hall, Thomas Sully installed his Gallery of Pictures from 1812 to 1822. Other tenants have included the United States District Court of Eastern Pennsylvania, the City of Philadelphia, and several investment and insurance brokers. The APS did not stop renting out space Philosophical Hall until 1934, when the Society was placed on secure financial footing courtesy of a significant bequest from its member Dr. Richard A. F. Penrose, Jr.

Philosophical Hall, ca.1940s (showing roof addition).Over the course of its history, agitators both external and internal have made motions for the Society to vacate Philosophical Hall for newer quarters. The first motion came in the 1830s and 1840s when the City of Philadelphia sought to acquire the Hall for its expanding judicial and administrative departments. Negotiations fell through, however, as a result of the five year depression following the Panic of 1837 and disagreements over price. Calls for a move were renewed in the second decade of the Twentieth Century when city planners proposed to transform the Benjamin Franklin Parkway into an American Champs Elysée along which the city's intellectual and cultural institutions would be situated. The issue was hotly debated among the membership, and was not finally resolved until receipt of the Penrose bequest signaled the end of the Society's financial problems.

Philosophical Hall undergoing renovation of its roof, 1948.During these years, space in Philosophical Hall became an increasingly critical problem, particularly for the library. In a first attempt to solve the problem, a third story was added to the Hall in 1890. This "dungeon-like" addition detracted not only from the Hall itself, but from the harmony of all of the original buildings on the Square, and worse, it proved insufficient to the needs of the rapidly expanding library. Within two decades a new solution was needed. In 1949, fifteen years after the library moved out of Philosophical Hall, the offending third story of was removed.

Today Philosophical Hall serves as the administrative headquarters for the APS. A 1998 renovation provided updated workspaces for its staff and better accessibility. In 1993, meetings of the Society were moved to more spacious accommodations in Benjamin Franklin Hall, the former Merchant's and Farmer's Bank at 427 Chestnut Street.