Athenaeum of Philadelphia; authors' use of this image under the partnership agreement between the Penn Libraries and the Athenaeum of Philadelphia, Almanac , 19 February 2019; image via Edward W. Duffy “Making & Breaking Of the Philadelphia Convention Center,” via Edward W. Duffy, “The Making & Breaking of the Philadelphia Commercial Museum,” https://hiddencityphila.org/2018/11/the-making-breaking-of-the-philadelp...