I've played Salisbury #4, which hosted a PGA tournament in the 20s (today's Eisenhower Park Red course), and it's quite good, probably a solid Doak 5, but I believe that one was private when the course opened..
The other courses Emmett built there don't exist anymore, and most of the land is taken up by two RTJ Sr. courses, which are pretty lackluster.
East Potomac Park is a mystery to me. It was originally designed by Travis, and couldn't get built right away because of WWI, so Robert White got it built just after 1920, but a more dull golf course I've not seen.
The property itself is simply dead flat, and the out and back routing is uninspiring. I guess at one time you could play the course in either direction, which is pretty cool and seemed to be sort of a fad for Travis, but the holes are so uninteresting you'd have to wonder who'd want to?
The only really exciting thing about EPP is that you get to aim some shots at the Washington Monument, and the Jefferson Memorial. Other than that, it's basic golf, perhaps generously a Doak 2, and I have to wonder if it changed or lost a lot of bunkering over the years?
I sure didn't see much signs of former greatness, or even goodness, however, in what remains.