The first scheme for the county prison was intended for a Market Street site. Plans were drawn and work begun when it was decided to build on a site to the rear of the courthouse. LeBrun was simultaneously supervising the construction of the Montgomery County jail ( MO22). This structure is similar with a central tower rising above a massive Gothic front, and recalls, as well, Thomas Walter's Moyamensing Prison (demolished) in Philadelphia. Here the front block is of local brownstone that interweaves through the rougher yellow sandstone of the nearby hills. Sandstone was used for the prison walls and for LeBrun's 1876 addition, built as the trial and execution of the Molly Maguires was reaching its tragic final act.