An amendment to the United States constitution that guarantees all American women citizens the right to vote, stating that “The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of sex.” This amendment was first introduced in Congress in 1878. After decades of lobbying, protests, parades, vigils, and hunger strikes by members of the women’s suffrage movement, the 19th Amendment was ratified in 1920.