America is only a geographical expression. Metternich's joke was made originally at the expense of Italy, but there are all too many modern states that have tried to build artificial national identities out of the ruins of historic and traditional regions -- the provinces, the sticks, the boondocks, the places where real people live, write poetry and pay their taxes.
In this respect, American Southerners have much in common with the Scots and the Welsh in Britain, the Lombards and Sicilians in Italy and the Ukrainians in the defunct Soviet Union. All have made enormous economic, military and cultural contributions to their imperial rulers, who rewarded their loyalty with exploitation and contempt.
In the United States, where ethnic slurs are punishable as hate crimes, it is still socially acceptable to describe Southerners as "rednecks" and "crackers," even though Southerners have, in fact, contributed to American culture, high and low, to a degree vastly out of proportion to their numbers.