Source:Darby
Wm. Darby. Plan of Pittsburg and Adjacent Country. R. Patterson and W. Darby, Philadelphia, 1815. Historic Pittsburgh DARMAP0197, DARMAP0198. Reproduced in John W. Reps, The Making of Urban America: A History of City Planning in the United States, p. 207, Princeton University Press, Princeton, N. J., 1965 (LCCN 63023414); and in Bruce J. Buvinger, The Origin, Development and Persistence of Street Patterns in Pittsburgh, Pennsylvania, p. 24. Also reproduced as "Plan von Pittsburg und Umgebungen" in Bernhard, Duke of Saxe-Weimar-Eisenach (Heinrich Luden, ed.), Reise Sr. Hoheit des Herzogs Bernhard zu Sachsen-Weimar-Eisenach durch Nord-Amerika in den Jahren 1825 und 1826, vol. II, following p. 200, Wilhelm Hoffmann, Weimar, 1828 (Internet Archive reisesrhoheitdes00bern, reisesrhoheitdes00inbern).
