James O'Hara and Isaac Craig opened Pittsburgh's first glass factory in 1797. They pioneered the glass industry in the area. The plant was located on the South Side, near where the Duquesne Incline parking lot at Station Square is today.(1) Later they became O'Hara Glass Company, Ltd. of Pittsburgh, Pennsylvania. They produced many of the very early pressed glass patterns and operated from 1848 - 1891. They were incorporated into the U.S. Glass Company after that.
Ref: South Side Facts: http://www.phlf.org/spotlightonmainstreet/resources/ss_facts_industry.pdf
