"The Fortifications at Whitemarsh" Topic

The above photo was sent to me by my mother and grandmother. It shows my Grandpop standing in the remains of Washington's 1777 fortifications at Whitemarsh. These were bulldozed and now lie under the Pennsylvania Turnpike, so photos like this are all that remain of them.

You can read more about the photo at link

Interesting. Where would that be situated?

EDIT: Just found this but not able to read it at the moment. Maybe of further interest. A pdf.

PDF link

Observance of the One Hundred and Twenty Third Anniversary
of the Evacuation of Philadelphia by the British Army.
Fort Washington and the Encampment at White Marsh, '
November 2, 1777 by RICHARD McCALL CADWALADER.

My grandfather is standing just to the right of where the road from Chestnut Hill crosses the fortifications, by the hexagonal redoubt. I teach at a school that happens to be just a few hundred yards from the spot, which is odd since my grandfather lived about ten miles away. Cadwalader is one of our graduates! The map was produced by the Hessian general Knyphausen's (sp?) staff, and while it is fairly accurate about the southern half where the British troops occupied, it is wildly inaccurate about the American positions. My students marvel at the mighty watercourse that the Wissahicon Creek appears to be. Today, the stream is about twenty feet wide at the most. Washington's headquarters were in the Emlen House, which is still standing but is in private hands. It's behind the Continental left, about halfway down the line.