(Formal Amending Method) An Amendment May be Proposed by a National Convention, Called by Congress When Requested by 2/3s (34) of the state legislatures. Then the Amendment is Ratified by the State Legislature of 3/4 (38) of the States. (Formal Amending Method) An Amendment May be Proposed by a National Convention, Called by Congress When Requested by 2/3s (34) of the state legislatures. Then the Amendment is Ratified by Conventions Held in 3/4 (38) of the States.