Q23. "What are the conditions needed for a Constitutional Convention, and when was the last one held?"
A. The Constitution itself has details about the calling of a Constitutional Convention, in Article 5. To have a Convention, two-thirds of all states (with 50 states, that's 34 states) must call for a Convention. There has never been a Constitutional Convention as detailed in the Article, though over time, many states have petitioned for one. All amendments to the Constitution have been through bills passed through Congress and then passed by the states. See the Amendments Page for more details.