We have three amendments to the US Constitution which address voting. The first is the 12th amendment, which gave poor white men the right to vote. Prior to this, voting was a privilege allowed only to white, landowning men. The second is the 15th amendment, allowing blacks the right to vote. And the third was the 19th amendment, which granted women the right to vote.

The last amendment to address who has the right to vote was just passed in 1920 — almost 100 years ago.