Which amendment to the U.S. Constitution gave American women a nationwide constitutional voting guarantee?

The Nineteenth Amendment gave American women a nationwide constitutional voting guarantee.

Congress approved 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, which is why August 26 is observed as Women’s Equality Day in the United States.

The amendment states that voting rights cannot be denied by the United States or a state on account of sex. It built on decades of organizing by suffragists, including Susan B. Anthony, Elizabeth Cady Stanton, Ida B. Wells, and many other activists.

The amendment did not instantly remove every barrier to voting. Many women of color, especially Black women in the South, still faced discriminatory laws, intimidation, and violence. Later federal legislation, including the Voting Rights Act of 1965, was essential to enforcing voting rights more broadly.