On August 2, 1920, Montana became the thirteenth state to ratify the 19th Amendment to the United States Constitution, granting women nationwide the right to vote. While the national amendment was certified later that month, Montana's ratification was a significant step in the long struggle for women's suffrage. Montana had a progressive history regarding women's voting rights, having granted women the right to vote in state elections in 1914, six years before the federal amendment.

This early adoption was largely due to the tireless efforts of suffragists like Jeannette Rankin, who would later become the first woman elected to the U.S. Congress.

The ratification of the 19th Amendment by Montana underscored the state's commitment to expanding democratic participation and recognized the crucial role women played in its development. This event is a testament to the persistent advocacy of suffragists and the evolving understanding of civil rights in the early 20th century, marking a pivotal moment in American history.