In the 19th century, the positioning of Pittsburgh as a major manufacturing center and the subsequent rise of the area's steel industry created a wave of prosperity that prompted the beneficiaries of that wealth to construct extravagant residences. Wealthy enclaves sprang up in the city's East End, across the river in neighboring Allegheny City, and into the countryside. Pittsburgh's Mansions explores the stately homes of the area's prominent residents from the 1830s through the 1920s. Businessmen such as H.J. Heinz, Henry Clay Frick, and members of the Mellon family commissioned elaborate homes from the preeminent architects of their day. Firms such as Alden & Harlow, Janssen & Abbott, and Rutan & Russell left their marks on the city's landscape, often contributing iconic public buildings as well as expansive private homes. Though many of the residences have since been lost, Pittsburgh's Mansions offers a look back at the peak of the city's prominence.