Which U.S. constitutional amendment prohibited denying the vote on the basis of sex?

The Nineteenth Amendment prohibited the United States and its states from denying the right to vote on the basis of sex.

Congress approved the amendment in 1919, and Tennessee supplied the decisive 36th state ratification on August 18, 1920. Secretary of State Bainbridge Colby certified the amendment on August 26, 1920, making that date the commonly observed anniversary of women’s constitutional suffrage.

The amendment was the result of decades of organizing, petitioning, public speaking, protests, and legal challenges. Leaders including Susan B. Anthony, Elizabeth Cady Stanton, Alice Paul, and Carrie Chapman Catt helped build the movement, although many other activists contributed to its success.

The amendment did not immediately remove every barrier to voting. African American women, Native American women, Asian American women, and Hispanic American women still faced discriminatory laws, citizenship restrictions, intimidation, poll taxes, literacy tests, and other obstacles. Its wording addressed sex discrimination, not every form of voting exclusion.