The federal Indian Citizenship Act passed in 1924. It granted US citizenship rights to all Native Americans. However, this did not guarantee the vote. States retained the authority to decide who could and could not vote. In 1926, Zitkála-Šá and her husband founded the National Council of American Indians. Until her death in 1938, she served as president, fundraiser, and speaker. The Council worked to unite the tribes across the United States to gain suffrage for all Indians. Zitkála-Šá also worked with white suffrage groups and was active in the General Federation of Women’s Clubs (GFWC) beginning in 1921. Zitkála-Šá created the Indian Welfare Committee of GFWC in 1924. That year, she ran a voter registration drive among Native Americans, encouraging those who could to engage in the democratic process and support legislation that would be good for Native Americans."
https://narf.org/the-indian-citizenship-act-at-100-years-old/