Under the Constitution of the United States, an example of a power reserved to the states is the power to

The power to coin money is explicitly granted to the federal government by the Constitution. Article I, Section 8 states that Congress has the authority to coin money and regulate its value, thereby centralizing monetary policy and preventing individual states from issuing their own currency.

Regulating interstate commerce is also a power assigned to the federal government, as outlined in Article I, Section 8. This clause allows Congress to manage trade between states and ensures a uniform economic environment, thereby preventing states from enacting conflicting trade regulations that could hinder economic growth.

The power to declare war is reserved for the federal government and is specifically given to Congress in Article I, Section 8 of the Constitution. This centralization of military authority ensures a unified national defense strategy, preventing individual states from independently engaging in military actions that could jeopardize national security.