The privileges and immunities clauses of the U. S. Constitution are integral to understanding the original American federal systems of rights. The framers of the US Constitution included the privileges and immunities clause in an attempt to promote comity among the states within the federal framework. American federalism is premised upon the dual citizenship of Americans, state and national. Justice Miller accomplished this by recognizing four essential components of federalism: state citizenship, state police powers, the federal basis of privileges and immunities, and the positive origins of acknowledged rights. Not only would a singular national citizenship negate privileges and immunities, but it would also significantly intrude upon the states' police powers. After acknowledging the "abstract justice which lies in the position of the plaintiffs in error," Justice Field delineates two types of restrictions on the police powers of the states, the constitutional prohibitions and fundamental principles.