You ask: “One thing I was wondering is there a place in the USA that makes and serves real ale as defined by this standard?”
So, let’s parse this question since there are really two parts: the brewery part and the beer bar part.
There is a brewery in Philadelphia, Yards Brewing, that regularly makes cask beer. The beer that they produce the most cask beer is ESA but they also provide other versions of their beer on cask. The next part of the ‘equation’ is the serving side; the beer bar. There are many beer bars in the Philly area that serve cask beer. The predominant serving method is via a beer engine (a hand pump). Some beer bars use cask breathers which provide a layer of CO2 on the cask; CAMRA disapproves of this method. Other beer bars serve the cask beer without a CO2 layer. So, there are some beer bars in the Philly area that serve cask beer via the CAMRA recommendations.
A ‘one stop’ place/brewery is Sly Fox which had a brewpub in Phoenixville, PA. They produce their Chester County Bitter on cask and serve it on a beer engine in their brewpub location (they are opening a tasting room at the production location in Pottstown, PA; it opens tomorrow).
Also, a number of Philly beer bars will have specials like Firkin Fridays where they will place the cask on a stillage on the bar and serve the beer via gravity pour. This meets the CAMRA guidelines.
I am sure that there are other breweries and beer bars in the US that serve cask ale per the CAMRA guidelines.