America (as in the United Sates of America) was "the great smelting pot" during the era in which the game is set . All the immigrants in question would have come through the cities of the East coast , and made their way west to the "open land" in the center of the country . While there is a few examples of settlements all originating from the same region of the old world , most were set up of a mixed groups of different back grounds all working together to make a new home . People were developing new customs not clinging to the old ways from where they had come from .
I dislike this idea completely . It leads to balkanization of peoples , not the blending together to form a new nation that was the soul of this era in United Sates history .
Plus it will lead to endless bickering . Russians shouldn't have that the Spanish were so much better at it . How can You not give that to the Italians ? etc. etc. etc.