Women's suffrage started in South Dakota when it was part of Dakota Territory. Prior to 1889, it had a shared history of women's suffrage with North Dakota. While South Dakota was part of the territory, women earned the right to vote on school related issues. They retained this right after it became a separate state. The state constitution specified that there would be a women's suffrage amendment referendum in 1890. Despite a large campaign that included Susan B. Anthony and a state suffrage group, the South Dakota Equal Suffrage Association (SDESA), the referendum failed. The state legislature passed additional suffrage referendums over the years, but each was voted down until 1918. South Dakota was an early ratifier of the Nineteenth Amendment, which was approved during a special midnight legislative session on December 4, 1919.