Seven years after the amendment was proposed it took into affect, and now DC has representation in congress to this day, and are even pushing for more rights.
24th Amendment: Prohibits both Congress and the states from conditioning the right to vote in federal elections on payment of a poll tax or other types of tax.
Historical background: The 24th amendment was brought up by Congress to the states on August 27, 1962, and was finally ratified by the states on January 23, 1964.
Historical Background: During the Vietnam war people protested that the legal age for voting was brought down from 21 to 18 because you could be drafted into the war at 18 why not have the right to vote as well.