Did founders of U.S.A. invite blowback by Blacks against there descendants by bringing the people as slaves?

Blowback meaning there Country own demise. By brining the slaves to America by the founders the European descendants today are suffering economically, in health and for the foreseeable future. The politicians created welfare states which hurt the central government and the states. A time will come when they will run a government as mayor and cause a complete change in the role of that big city government and all the blacks who where outcast will become police men and the mayor will builds a police force into a military and we cannot stop the build up because the mayor has a right to higher and train. The mayor and that council of blacks. Did founders of U.S.A. invite by Blacks against there will create a government within a government. Then what? What happens if they contract to fight wars oversees and build up enough credibility to say no to county government no to state government and no to federal government. They will be strong by uniting all the black to a city.