Jeannette Pickering Rankin, the first woman ever elected to Congress, takes her seat in the U.S. Capitol as a representative from Montana.

Born on a ranch near Missoula, Montana Territory, in 1880, Rankin was a social worker in the states of Montana and Washington before joining the women’s suffrage movement in 1910. Working with various suffrage groups, she campaigned for the women’s vote on a national level and in 1914 was instrumental in the passage of suffrage legislation in Montana. Two years later, she successfully ran for Congress in Montana on a progressive Republican platform calling for total women’s suffrage, legislation protecting children, and U.S. neutrality in the European war. Following her election as a representative, Rankin’s entrance into Congress was delayed for a month as congressmen discussed whether a woman should be admitted into the House of Representatives.

Finally, on April 2, 1917, she was introduced in Congress as its first female member. The same day, President Woodrow Wilson addressed a joint session of Congress and urged a declaration of war against Germany. On April 4, the Senate voted for war by a wide majority, and on April 6 the vote went to the House. Citing public opinion in Montana and her own pacifist beliefs, Jeannette Rankin was one of only 50 representatives who voted against the American declaration of war. For the remainder of her first term in Congress, she sponsored legislation to aid women and children, and advocated the passage of a federal suffrage amendment.

In 1918, Rankin unsuccessfully ran for a Senate seat, and in 1919 she left Congress to become an important figure in a number of suffrage and pacifist organizations. In 1940, with the U.S. entrance into another world war imminent, she was again elected as a pacifist representative from Montana and, after assuming office, argued vehemently against President Franklin D. Roosevelt’s war preparations. On December 7, 1941, the Japanese attacked Pearl Harbor, and the next day, at Roosevelt’s urging, Congress passed a formal declaration of war against Japan. Representative Rankin cast the sole dissenting vote. This action created a furor and Rankin declined to seek reelection. After leaving office in 1943, Rankin continued to be an important spokesperson for pacifism and social reform. In 1967, she organized the Jeannette Rankin Brigade, an organization that staged a number of highly publicized protests against the Vietnam War. She died in 1973 at the age of 93.

READ MORE: 7 Things You May Not Know About Jeannette Rankin