Question

Which method of formal amendment has been used only once

Answer 1

The method of ratifying conventions in three-fourths of the states has been used only once to amend the Constitution, specifically to ratify the 21st Amendment.

Step-by-step explanation:

The method of ratifying conventions in three-fourths of the states has been used only once to amend the Constitution. This method was used to ratify the 21st Amendment, which repealed Prohibition. Ratifying conventions were held in three-fourths of the states, and when the amendment was approved in enough states, it became a part of the Constitution.

Answer 2

This method is ratification by convention or state ratifying conventions- where two thirds of the states call a convention to propose an amendment. The only time it was used was in 1933 when the Prohibition of Alcohol was repealed.