Which article in the US Constitution addresses the power of the states?

The article in the US Constitution that addresses the power of the states is Article IV. This article outlines the relationship between the states and the federal government and includes provisions about the powers and responsibilities of the states. It establishes the concept of full faith and credit, which requires states to recognize the laws and judicial proceedings of other states. Additionally, Article IV contains provisions regarding the privileges and immunities of citizens, the admission of new states, and the protection of states against invasion and domestic violence.

Understanding the context of Article IV is vital for grasping the balance of power in the federal system. It reflects the framers' intention to create a federation that preserves a degree of sovereign authority for states while ensuring cooperative functioning within the national framework. This is foundational for discussions around federalism and the limits of state authority compared to federal power.