article v the congress ... on the application of the legislatures of two thirds of the several states , shall call a convention for proposing amendments , which ... shall be valid to all intents and purposes , as part of this constitution , when ratified by the legislatures of three fourths of the several states , or by conventions in three fourths thereof united states constitution prelude in 2014 and 2015 , by executive order , the southern border of the united states was opened to all who wanted to cross .