When was the first woman elected to the United States Congress?

Jeannette Pickering Rankin (June 11, 1880 – May 18, 1973) was the first woman to hold federal office in the United States when, in 1916, she was elected to the U.S. House of Representatives by the state of Montana. She won a second House term 24 years later, in 1940. Interestingly, Ms. Rankin, who was a lifelong pacifist served in the House when war was declared in 1917 and in 1941. She was one of 50 house members that voted against the declaration of war in 1917 and the only person that opposed declaring war on Japan after Pearl Harbor. She was also very instrumental in initiating the legislation that would become the 19th amendment granting women the right to vote.