The Nineteenth Amendment (Amendment XIX) to the United States Constitution prohibits the states and the federal government from denying the right to vote to citizens of the United States on the basis of sex. Initially introduced to Congress in 1878, several attempts to pass a women’s suffrage amendment failed until passing the House of Representatives on May 21, 1919, followed by the Senate on June 4, 1919. It was then submitted to the states for ratification. On August 18, 1920, Tennessee was the last of the necessary 36 states to secure ratification. The Nineteenth Amendment was officially adopted on August 26, 1920: the culmination of a decades-long movement for women’s suffrage at both state and national levels.

Prior to 1776, women had the right to vote in several of the colonies in what would become the United States, but by 1807 every state constitution denied even limited suffrage. Organizations supporting women’s rights became more active in the mid-nineteenth century. Black women such as Sojourner Truth and Harriet Tubman were major organizers of the early women’s suffrage movement while also advocating for the15th Amendment. In 1848, the Seneca Falls convention adopted the Declaration of Sentiments, which called for equality between the sexes and included a resolution urging women to secure the vote. Pro-suffrage organizations used a variety of tactics including legal arguments that relied on existing amendments. After those arguments were struck down by the U.S. Supreme Court, suffrage organizations, with activists like Ida B. Wells, Mary Church Terrell, Susan B. Anthony and Elizabeth Cady Stanton, called for a new constitutional amendment that would guarantee women the right to vote.