Final answer:
The only method used to propose an amendment thus far is when two-thirds of both chambers of Congress agree to the proposal, or when two-thirds of the states call a convention to propose an amendment.
Step-by-step explanation:
The only method used to propose an amendment thus far is when two-thirds of both chambers of Congress agree to the proposal, or when two-thirds of the states call a convention to propose an amendment. However, to date, this method has never been used.