What do federal laws supersede in the hierarchy of laws?

Federal laws have supremacy over both state laws and local laws within the framework of the United States legal system. This principle stems from the Supremacy Clause of the Constitution, found in Article VI, which establishes that the Constitution, federal laws, and treaties made under its authority take precedence over any conflicting state laws or local ordinances.

When federal law is enacted, it applies uniformly across all states, meaning that if a state law contradicts a federal law, the federal law will prevail, and the state law will be rendered invalid. This hierarchy ensures consistent legal standards across the nation and prevents states from enacting laws that may undermine federal legislation. By specifying both state and local laws, the correct answer encapsulates the full scope of federal authority in relation to other laws within the United States.