In 1848, the U.S. women’s suffrage movement coalesced in Seneca Falls, NY, where 300 women and men gathered for a two-day women’s rights convention. Their call for women’s suffrage spread across the country in the decades that followed. Supporters of the movement quickly discovered change would be frustratingly slow.

On Jan. 10, 1918, the House of Representatives approved a constitutional amendment granting women the right to vote. The amendment was introduced in the Senate that September, and President Woodrow Wilson gave a rousing speech in support of it. But the Senate failed to pass the amendment. Suffragists continued their public protests until Wilson called for a special session of Congress.

The amendment finally passed in the House in May 1919 and in the Senate in June 1919. The tremendously difficult process of ratification, which requires three-quarters of all states (36 of 48 states at the time), took another year.

The 19th Amendment was added to the Constitution on Aug. 26, 1920.

Inspired by historic photographs, the stamp art features a stylized illustration of suffragists marching in a parade or other public demonstration. The clothes they wear and the banners they bear display the official colors of the National Woman’s Party — purple, white and gold.