A fascinating aspect of this question is that the two most recently ratified amendments represent both the fastest and slowest examples. In 1971 it took only 99 days for the people to nullify a controversial and deeply divided court decision. Then in 1992 after lying open for 74003 days (202 years), one of the original elements of the bundle included with the Bill of Rights was ratified.
The Date Approved is when Congress (or a constitutional convention) voted to by a 2/3 majority to send the amendment to the States for ratification. The Date Ratified is when the 3/4 (of the States) quota had been reached. The dates are given in YYYY/MM/DD format for ease of comparison.
|Date Approved||Date Ratified||Elapsed Time|