The Nineteenth Amendment took effect on August 18, 1920, after Tennessee became the thirty-sixth state to ratify it.
The amendment prohibited the United States and its states from denying citizens the right to vote on the basis of sex. Congress had passed it in 1919, after decades of organizing by suffrage activists including Susan B. Anthony, Elizabeth Cady Stanton, and Alice Paul.
The amendment's adoption is often associated with August 26, 1920, but that was the date the U.S. secretary of state certified the ratification. The legal threshold was reached eight days earlier, when Tennessee's legislature approved the amendment.
The amendment was a major milestone, but it did not immediately guarantee equal voting access to every woman. Discriminatory laws and practices continued to prevent many African American, Native American, Asian American, and Latina women from voting. Further federal legislation and court decisions were needed to challenge those barriers.