Hummelstown Brownstone Company

From 1863 to 1929, the Hummelstown Brownstone Company owned and operated quarries in the Hummelstown, Pennsylvania area which produced Hummelstown brownstone, once widely used as a building stone throughout the US. The quarries of the Hummelstown Brownstone Company are listed on the National Register of Historic Places. == History and operations == Hummelstown brownstone pits were first opened by early German settlers in the late 18th Century.

Source: Wikipedia — Hummelstown Brownstone Company (CC BY-SA 4.0)