William Knabe & Company Piano Factory, ca. 1873

Upon their arrival in Baltimore, all four Potthast brothers immediately found work at the Knabe Piano Factory, which had been founded by first-generation German immigrant William Knabe. At the time, Knabe was a leading American piano manufacturer.

Source: George W. Howard, The Monumental City, Its Past History and Present Resources. J. D. Ehlers & Co., Baltimore, 1873, p. 307.