A photograph captures a close-up of a section of the U.S. Constitution displaying Amendment X under the "Bill of Rights" header. — The Tenth Amendment of the U.S. Constitution emphasizes the reserved powers of the states and the people.

US Amendment 10: Reserved Powers and the Foundation of US Law

Author Name: Nahyan | uslawguide

Last Updated: June 28, 2025

The US Amendment 10, seemingly simple in its declaration, is a profound cornerstone of American federalism, explicitly defining the boundaries of federal power and reserving vast authority to the states and the people. This fundamental principle directly shapes the scope and nature of US laws, dictating which level of government can act and where its authority ends. It serves as a constant reminder that the federal government is one of limited, enumerated powers, and that a significant sphere of governance, including the power to create and enforce many types of laws, remains with the states or the citizenry. This concept is frequently central to legal challenges involving constitutional amendment procedures and Supreme Court decisions addressing state sovereignty. For example, the National Constitution Center offers insight into how the Tenth Amendment frames contemporary disputes over states’ rights.

Historical Context: Anti-Federalist Concerns and the Birth of US Amendment 10

The inclusion of the US Amendment 10 in the Bill of Rights was a direct response to the intense debates surrounding the ratification of the U.S. Constitution. Anti-Federalists, who opposed the strong central government proposed by the Constitution, feared that without explicit limitations, the new federal entity would eventually usurp state sovereignty and individual liberties. They pointed to clauses like the “Necessary and Proper Clause” (Article I, Section 8) and the “Supremacy Clause” (Article VI) as potential avenues for an unchecked federal government to make laws that encroached on powers traditionally held by the states. The US Amendments Bill of Rights, especially the Tenth Amendment, was therefore seen as a vital safeguard against federal overreach. Today, scholars and legal experts still debate the amendment’s practical limits on federal authority—an issue discussed in detail at the Library of Congress.

The Core Legal Provisions of US Amendment 10

The full text of the US Amendment 10 is concise and impactful:

“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.”

Let’s break down its key elements and their direct impact on law-making authority:

“The powers not delegated to the United States”: This refers to powers that are not explicitly or implicitly granted to the federal government in the Constitution. For example, the federal government has delegated powers to coin money, declare war, and regulate interstate commerce. Any powers not falling under these delegated categories cannot be exercised by federal laws.
“nor prohibited by it to the States”: This acknowledges that while states retain broad authority, some powers are explicitly denied to them by the Constitution. For instance, states cannot make treaties, coin their own money, or pass ex post facto laws (laws that retroactively criminalize actions).
“are reserved to the States respectively, or to the people”: This is the heart of the amendment and establishes two distinct spheres of reserved power:
- Reserved to the States: These are often referred to as the “police powers”—the broad authority of states to pass laws for the health, safety, welfare, and morals of their citizens. This includes the vast majority of criminal laws, education laws, family laws (marriage, divorce), most contract and property laws, and many environmental laws specific to intrastate issues. States can innovate and tailor laws to their unique populations and needs.
- Reserved to the People: This clause acknowledges individual rights and liberties not explicitly listed in the Constitution but retained by the citizenry. It reinforces concepts of popular sovereignty and unenumerated rights (as also suggested by the 9th Amendment), influencing the general limits on all governmental laws, whether federal or state.

Judicial Interpretations: The Dynamic Balance of Power in US Law

The significance of the US Amendment 10 has fluctuated throughout American history, reflecting ongoing debates about federalism and the proper scope of US laws.

Early Views (e.g., McCulloch v. Maryland, 1819): While not directly interpreting the 10th Amendment, Chief Justice John Marshall’s broad interpretation of federal implied powers and the “Necessary and Proper Clause” in McCulloch initially seemed to lessen the 10th Amendment’s constraining force on federal laws. Marshall famously stated that the 10th Amendment “is merely declaratory” and does not “superadd a limitation” on federal powers that are otherwise legitimate.
Revival and Fluctuation: The 10th Amendment’s practical impact has seen periods of greater and lesser emphasis:
- Early 20th Century (“Dual Federalism”): During this era, the Supreme Court sometimes interpreted the 10th Amendment to create a stricter separation between federal and state powers, occasionally invalidating federal laws seen as infringing on reserved state powers (e.g., federal child labor laws were struck down for interfering with state control over manufacturing).
- New Deal Era & Beyond: The scope of federal power, particularly under the Commerce Clause, expanded dramatically in response to economic crises. Cases like United States v. Darby Lumber Co. (1941) effectively reverted to Marshall’s view, stating that the 10th Amendment “states but a truism” and does not limit federal power when that power is exercised within the bounds of the Constitution. For decades, the 10th Amendment was largely seen as having little practical limiting effect on federal laws.
- Modern Revival (1990s onward): The Supreme Court has shown renewed interest in the 10th Amendment as a substantive limit on federal power, particularly in cases involving “anti-commandeering” principles:
  - New York v. United States (1992): The Court struck down a federal law that compelled states to “take title” to radioactive waste, establishing the “anti-commandeering” doctrine. This principle holds that Congress cannot compel states to enact or enforce federal regulatory programs, directly impacting federal legislative strategies and state compliance with federal laws.
  - Printz v. United States (1997): This case extended the anti-commandeering principle, holding that Congress cannot compel state or local law enforcement officers to conduct background checks for federal gun laws. This further clarified the limits of federal power over state executive branches and their ability to enforce federal laws.

Impact on Federalism and the Scope of US Laws

The US Amendment 10 is fundamental to the American system of federalism, profoundly shaping the division of governmental authority and the scope of US laws:

Defining Spheres of Governance: It clarifies that states possess broad authority to make laws on matters not explicitly delegated to the federal government. This includes the vast majority of laws directly affecting daily life, such as criminal laws, environmental regulations, education standards, healthcare policies, and civil laws governing contracts and property.
Limits on Federal Overreach: The amendment acts as a constitutional check, ensuring that federal laws do not unduly intrude on areas traditionally reserved for state action. This promotes a decentralized approach to governance, allowing for diverse state approaches to policy and law.
Policy Innovation: States are often referred to as “laboratories of democracy.” The 10th Amendment allows them to experiment with different laws and policies without direct federal interference, fostering innovation and allowing for tailored solutions to local problems.
Ongoing Debates: The 10th Amendment remains central to contemporary debates on a wide range of issues where federal and state powers intersect and sometimes clash. Examples include differing state and federal laws on cannabis, variations in healthcare regulations, environmental protection standards, and approaches to immigration enforcement.

Conclusion

The US Amendment 10 is far more than a historical artifact; it is a vital, living principle that constantly shapes the contours of US law and the American federal system. It serves as a foundational declaration of limited federal power, safeguarding state autonomy and fostering a robust, decentralized approach to law-making in the United States. Its enduring presence in constitutional jurisprudence ensures that the balance of power between the national government and the states remains a dynamic and often debated aspect of American governance, reminding us that the ultimate authority to create and enforce many laws resides closest to the people.

Frequently Asked Questions About US Amendment 10

Q: What is the main purpose of US Amendment 10? A: The main purpose of the US Amendment 10 is to define the division of powers between the federal government and the states. It clarifies that any powers not specifically given to the federal government by the Constitution, nor prohibited to the states, are reserved for the states or the people, directly impacting the scope of US laws.

Q: What are “reserved powers” according to the 10th Amendment, and how do they relate to laws? A: “Reserved powers” are those governmental powers that belong to the states or the people because they were not delegated to the federal government by the Constitution. These powers allow states to pass laws on a wide range of issues affecting their citizens’ daily lives, such as criminal laws, education laws, and public health regulations.

Q: How does the 10th Amendment influence federal vs. state laws? A: The 10th Amendment influences federal vs. state laws by limiting the federal government’s ability to legislate in areas not explicitly granted to it by the Constitution. This leaves a broad scope for states to create their own laws tailored to their specific needs and values, fostering a diverse legal landscape across the country.

Q: What is the “anti-commandeering” principle, and how does it relate to US Amendment 10? A: The “anti-commandeering” principle, derived from the US Amendment 10, states that the federal government cannot compel states to enact or enforce federal regulatory programs or require state officials to administer federal laws. This protects state sovereignty and prevents the federal government from forcing states to act as its agents.

Q: Has the Supreme Court always interpreted the 10th Amendment in the same way regarding federal laws? A: No, the Supreme Court’s interpretation of the 10th Amendment’s impact on federal laws has varied over time. While it was initially seen as a mere truism, it gained more substantive limiting power in the early 20th century, then receded during the New Deal era, and has seen a resurgence in the 1990s with the development of the “anti-commandeering” doctrine.

Responsible Disclaimer: This article provides general information about US Amendment 10 and its historical and legal context. It is not intended as legal advice. For specific interpretations of constitutional law or legal counsel regarding particular laws or federal-state disputes, readers should consult a qualified attorney provider.