This is necessary so that interstate commerce can occur under one set of laws and regulations, and also that the federated nation of states (U.S.A.) may be defended as one (from attack by another country, for instance).
What is not necessary to regulate, from a federal standpoint, is left to each state to decide for itself.
The United States calls its form of government where its power is divided between the national and state governments a Federal System. It created that type of government. In that case, the national government has responsibility for certain aspects and the state governments have responsibility for certain aspects. In France and England almost all power resides at the national level while administration occurs at the local level.
federal and state governments.
Federal republic refers to a type of government which has a central government sharing power with several state governments.
building roads.
national and state
The national government, not the state governments.
in a federal government, the power is divided between the central and local governments.
A national government and state governments
The part of a government that holds power in a confederacy is the state government. The federal government has limited power in this government.
federal
federal
The national government, not the state governments.