Source:Hillsborough-alley-agreement-1807
From Pittsburgh Streets
Stewart Bailey, Robert Cummings, Hugh Marshel, and William Mitchel. Articles of agreement for the opening of Hillsborough Alley. Aug. 4, 1807. In the papers of the Campbell family, 1807–1873, MSS #4, Historical Society of Western Pennsylvania, Detre Library and Archives, Heinz History Center (see Historic Pittsburgh US-QQS-MSS4).
