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Congressional Apportionment Amendment - Wikipedia
In the 1st United States Congress, James Madison put together a package of constitutional amendments designed to address the concerns of Anti-Federalists, who were suspicious of federal power under the new constitution. The Congressional Apportionment Amendment is the only one of the twelve amendments passed by Congress which was never ratified; ten amendments were ratified by 1791 as the Bill of Rights, while the other amendment (Article the Second) was later ratified as the Twenty-seventh Amendment in 1992. A majority of the states did ratify the Congressional Apportion Amendment and, by the end of 1791, the amendment was just one state short of adoption. However, no state has ratified the amendment since 1792.
