The roots of Congressional would be.... what exactly? Let's review:
Devereux Emmet laid out the original course in 1924, I believe. That course occupied the land of the present Blue front nine (with a rather different routing), and nine holes of the present Gold (with fewer routing changes). Dan Wexler shows the old front nine in his book.
In 1930, it seems Donald Ross made some changes, though I think that is disputed.
In 1957, with the club trying to get the 1964 Open, RT Jones built an entirely new nine holes on an adjoining piece of land. That became the back nine of the present Blue Course. However, the USGA didn't want to finish on the par-3 18th, so that hole was deleted from the tournament setup (along with the 16th) and two of Emmet's holes became the 16th and 17th holes for Open purposes.
At this time, Jones also completely re-routed Emmet's front nine. Emmet's 2nd, 7th, and 8th holes were included in the new routing -- but they were the 5th, 4th, and 3rd respectively. Detail-wise, the whole course was done up in a flashed-face bunker style and got new tree plantings.
When the 1997 Open was awarded to Congressional, the USGA and the club wanted to hark back to a more "classic" look and had Rees Jones redo all the bunkers with grass faces. I guess as a "quaint" historical reference they also decided to "restore" RT Jones's par-3 18th (from the old days of 1957, haha), and bring back his old 16th hole too. The two Emmet holes went back to be a permanent part of the Gold Course, now expanded to 18 holes.
None of this exactly made the Blue Course a classic Golden Age gem.
That par-3 18th was actually sort of a pain in the butt during that 97 Open, so for the 2011 Open a new and awful REVERSED version was created which became the 10th, permanently shifting the entire back nine sequence one hole. Like the third at Inverness, that hole sticks out like a sore thumb.
So, what's the point of "restoring" any of that? Now, to be fair I don't think Congressional is such a bad golf course. However, just because Devereux Emmet started the project out in the 1920s, that doesn't make it a "classic" worthy of note. It's a product of the architectural Dark Ages that has been cared for well enough to be a decent place to play.
Even in Maryland (not exactly a golf-heavy state like NJ or PA), Congressional can't compete well with Baltimore CC Five Farms (East).