There is not a specific antonym for diaspora, but the opposite of a diaspora would be the regrouping of a community or the coming together of a community. It could also be a renewal of a specific cultural group or ethnicity coming back together in a sort of revival of their culture.
I belive its dance halls.. please let me know if i am wrong
The essence of open range was the free grazing of cattle on millions of unfenced acres of public land. It was possible to become wealthy raising cattle without owning any acreage. Although most ranchers owned a base operation, some owned millions of acres. America's open range started with the Civil War [1861-1865].