Which amendment to the US Constitution declares that the Federal Government does not have any power that the US Constitution hasn?

The Tenth Amendment to the U.S. Constitution declares that powers not delegated to the Federal Government by the Constitution, nor prohibited to the States, are reserved to the States or to the people. This amendment emphasizes the principle of federalism and limits the scope of federal authority. It ensures that any powers not explicitly granted to the federal government remain with the states or the citizens.