The 15th Amendment gave African American men the right to vote in 1870. But many weren't able to exercise this right. Some states used literacy tests and other barriers to make it harder to vote.
The 19th Amendment, ratified in 1920, gave American women the right to vote.
The 24th Amendment, ratified in 1964, eliminated poll taxes. The tax had been used in some states to keep African Americans from voting in federal elections.
The 26th Amendment, ratified in 1971, lowered the voting age for all elections to 18.