Map of a reconnaissance of the approaches to Philadelphia showing the positions and lines of defence on the north front of the city /

Topographic map of northern Philadelphia and small adjacent part of Montgomery County showing Civil War earthworks and batteries.
Relief shown by contours and hachures.
Signed in handwriting (brown ink): George Davidson, Assistant Engineer Fortifications.
Pen-and-ink, red ink (contours), and watercolors.
Former ownership rubber-stamping at foot of title: U.S.C. & G. Survey, Library and Archives, no. 126.
"No. 2868X" and "854W 1863" (former Coast Survey numbers) are handwritten in ink on each sheet and on adhesive label at corner of sheets.
Sheet numbered in blue pencil at top: Sheet 1 [thru] Sheet 10.
Imperfect: Brittle, missing small internal and edge sections.
Includes notes.
LC Civil War Maps (2nd ed.), 358.3
Available also through the Library of Congress Web site as a raster image.