I ran into this sample book of Conkling ~ Armstrong Terra Cotta Company in Philadelphia. I always thought a lot of the decoration on older buildings was carved stone. Most of it was probably terra cotta which is now pretty much a lost architectural art form. Here are some samples from the book and the buildings they adorn in Philly.
[Port-folio] (Open Library)
Philaphilia: Old-Ass Building of the Week-- July 4th
1420-22 Chestnut St. Constructed in 1899; steel-framed and clad with non-load-bearing terra cotta and pompeian brick.
Architect: Frank Miles Day, known for his effectiveness in revival styles.
Architecture: French Renaissance (particularly upperframed levels) reflecting the era of Francois I, "combining the principle strains of western art ~ the classic, and the gothic, in a synthetic style sanctioned by history and having the happy result of leaving an elegant bit of French chateau elevated in the skyline. . ." ~ George Thomas.
The Crozer Building was added to the National Register of Historic Places in 1980.