Time Limits on Proposed Constitutional Amendments
I was reading the Constitution the other day (doesn’t everyone?) and I noticed something that I hadn’t focused on before. The Eighteenth Amendment was the first one to contain a time limit for the ratification process, holding that the proposal would be inoperative it did not receive the necessary three-fourths of the states within seven years. The Twentieth, Twenty-First, Twenty-Second Amendments had a similar provision, as did the unsuccessful Equal Rights Amendment.
The Nineteenth, Twenty-Third, Twenty-Fourth, Twenty-Fifth, and Twenty-Sixth Amendments, though, did not have a ratification time limit in them. (The Twenty-Seventh, which was proposed in 1791 and ratified in 1992 obviously had none.) Why this inconsistency? Does anyway know why some amendments had a time limit and some did not?