Non-white men: 1870 — See: Fifteenth Amendment to the United States Constitution Women: 1920 — See: Nineteenth Amendment to the United States Constitution Native Americans: 1924 [4] Residents of the District of Columbia: 1961 — See: Twenty-third Amendment to the United States Constitution Poor: 1964 — See: Twenty-fourth Amendment to the United States Constitution, prohibiting imposition of poll tax in Federal elections Adults between 18 and 21: 1971 — See: Twenty-sixth Amendment to the United States Constitution