under the U.S. constitution which level of government retains powers not delegated to the national government

Under the U.S. Constitution, powers not delegated to the national government are retained by the states. This principle is established in the Tenth Amendment, which states: "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." This amendment emphasizes the federal structure of the United States, where both the national and state governments have their own distinct powers.