Which amendment to the United States Constitution gave women nationwide voting rights in 1920?

The Nineteenth Amendment gave women nationwide constitutional protection for voting rights in the United States.

Congress proposed the amendment in 1919, and Tennessee became the decisive thirty-sixth state to ratify it on August 18, 1920. Secretary of State Bainbridge Colby certified the amendment on August 26, 1920, making that date the formal anniversary commonly observed as Women’s Equality Day.

The amendment states that voting rights cannot be denied by the United States or by a state on account of sex. It followed decades of organizing, petitioning, public speaking, demonstrations, and legal campaigns by women’s suffrage activists. Leaders included Susan B. Anthony, Elizabeth Cady Stanton, Ida B. Wells, Carrie Chapman Catt, and Alice Paul.

Ratification did not immediately eliminate every barrier to voting. Many women of color continued to face discriminatory state laws, intimidation, violence, literacy tests, poll taxes, and other obstacles. The amendment was therefore a major constitutional milestone, but the struggle for equal access to the ballot continued long afterward.