What is a constitutional amendment?

A constitutional amendment refers to a formal change or addition to the Constitution itself. This process typically involves a rigorous procedure where a proposed amendment must be approved by a significant majority in both houses of Congress and subsequently ratified by a certain number of state legislatures. The purpose of amending the Constitution allows for the document to evolve over time, addressing social, political, or legal changes within the society it governs.

In contrast, the other options do not align with the concept of a constitutional amendment. State laws are laid out in legal documents but these do not affect the overarching national Constitution or signify a change to it. A proposal for national legislation refers to initiatives aimed at creating new laws rather than modifying the foundational principles encapsulated in the Constitution. A declaration of independence typically denotes a formal statement by a group breaking away from a sovereign entity, which is distinct from modifying an existing legal document like the Constitution.