Which amendment to the U.S. Constitution prohibited denying voting rights on the basis of sex?

The Nineteenth Amendment prohibited denying U.S. citizens the right to vote on the basis of sex.

Congress approved the amendment in 1919 after decades of organizing by women’s suffrage activists. The amendment states that the voting rights of U.S. citizens cannot be denied or abridged by the United States or any state because of sex. It was the culmination of campaigns that included conventions, petitions, marches, public speaking, and civil disobedience.

Tennessee became the 36th state to ratify the amendment on August 18, 1920, providing the required number of state approvals. Secretary of State Bainbridge Colby certified it on August 26, 1920. That date is commemorated in the United States as Women’s Equality Day.

The amendment did not instantly remove every barrier to voting. Many women of color continued to face discriminatory laws and practices, especially in states where Black voters were suppressed. Later federal legislation and court decisions were necessary to challenge those barriers.