Congress has the authority to regulate commerce between which entities?

The authority of Congress to regulate commerce between states is rooted in the Commerce Clause of the United States Constitution, specifically in Article I, Section 8, Clause 3. This clause grants Congress the power to regulate commerce "among the several states," which means that Congress can create laws that affect trade and economic interactions between different states.

This power has significant implications, as it allows for the establishment of a common market among the states, preventing any single state from imposing barriers that could hinder trade with other states. This has historically facilitated a more integrated national economy and avoided conflicts that might arise from differing state regulations.

While individuals, foreign nations, and corporations may also be involved in commerce, the specific authority Congress has to regulate commerce directly pertains to the relationships and economic interactions between states. This foundation is crucial in understanding the balance of power between state and federal governments, especially in regard to economic and trade matters.