Among their surviving major works are the Pennsylvania Railroad, Connecting Railway Bridge over the Schuylkill River (1866–67), the main building of Drexel University (1888–91), and the train shed of Reading Terminal (1891–93), all located in Philadelphia.
For a PRR subsidiary, he designed the Baltimore & Potomac Railroad Passenger Terminal in Washington, D.C. (1873–77, demolished 1908), the station in which U.S. President James A. Garfield was assassinated in 1881.
For the 1876 Centennial Exposition, Henry Petit and Joseph M. Wilson co-designed the Main Exhibition Building—the largest building in the world, 1,876 feet (572 m) in length and enclosing 21-1/2 acres.
In Beach Haven, New Jersey, it designed the Baldwin Hotel (1883, burned 1960), Holy Innocents Episcopal Church (1881–82), and a number of summer homes for company executives.
In response, Joseph Wilson designed the Drexel Building, a 10-story, H-shaped addition that surrounded Independence National Bank on the east, west and south sides, permanently depriving the neighbor of sunlight.
In an ironic turn of events, the Drexel Building itself was demolished in 1959, and a replica of Library Hall was built on its original site by the American Philosophical Society.