Bill of Rights · 10th Amendment
Tenth Amendment
Ratified December 15, 1791
Verbatim
Exact text as ratified.
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.
Plain English
A translation that drops archaic words but keeps the meaning, including the parts courts still argue about.
Any power that the Constitution does not give to the federal government, and does not forbid the states from having, belongs to the states or to the people.
What this means for you
The Tenth Amendment is the foundation of federalism, the system of dividing power between the federal government and the states. It says the federal government has only the powers the Constitution gives it; everything else stays with the states or with the people directly.
In practice, the line between federal and state power is one of the most contested questions in American law. The federal government's powers are listed mainly in Article I, Section 8 (Commerce Clause, taxing power, spending power, and others), and they have been read both broadly and narrowly at different points in history. The Tenth Amendment is what courts and political actors point to when arguing that the federal government has overstepped.
For ordinary daily life, this amendment explains why states can have very different laws — why marijuana is legal in some states and not others, why marriage and divorce rules vary by state, why driver's license rules differ. These areas were never delegated to the federal government, so they remained with the states.
About
The Tenth Amendment was ratified in 1791 and was largely a restatement of a principle the founders considered already implicit in the Constitution: that the federal government has only the powers granted to it. The amendment was added to make this principle textually explicit and to reassure states wary of federal power.
The Supreme Court has read the Tenth Amendment differently in different eras. From roughly 1937 to 1995, the Court rarely struck down federal laws on Tenth Amendment grounds, generally deferring to broad readings of the Commerce Clause and other federal powers. Beginning with United States v. Lopez (1995), the Court began enforcing limits on federal power more actively, and recent cases have continued this trend.
The phrase "or to the people" at the end of the amendment has been read by some scholars as recognizing that some powers belong directly to individuals rather than being routed through state governments, though this reading has not been heavily developed in case law.