Final answer:
Jeannette Rankin was the first woman to serve in the U.S. Congress.
Step-by-step explanation:
The first woman to serve in the U.S. Congress was Jeannette Rankin. She was elected to the House of Representatives in 1916, four years before women gained the right to vote in the U.S. She represented the state of Montana and was a prominent figure in the suffrage movement.
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