Seventh street bridge
Photo taken by Douglas Butler in May 2013
License: Creative Commons Attribution (CC BY)
BH Photo #287614
The Hagley aerial photo in the link clearly shows an open swing truss bridge.
The old 7th street bridge was a fixed truss, not a swing truss as indicated.
That is the Christina River; I think the most likely place for this bridge would be 39.732426, -75.530334
East 7th at Brandywine Creek.