... "The powers not delegated to the United States by the Constitution, nor prohibited by it to the states, are reserved to the states respectively, or to the people."
At the year 630 when 30K muslims marched to mecca.
The following is a union of independent sovereign states:
In 1991,USSR president Mikhail Gorbachev recreated USSR in to a union of independent sovereign states by signing a 9+1 Treaty to make USSR into a Confederation.
For one they were just plain racists lol. But also because they know that the only thing keeping them in office was suppressing African-American votes through Jim Crow, KKK, poll tests.