How are changes made to the U.S. Constitution?

Article V establishes two routes for proposing amendments: two-thirds vote in both houses of Congress (used for all twenty-seven amendments so far) or a constitutional convention called by two-thirds of state legislatures (never used). Ratification requires approval by three-fourths of state legislatures or state conventions. This high threshold reflects the Framers' intent to prevent temporary majorities from rewriting foundational law while still allowing necessary evolution.