Women fought for the right to vote since the mid-1800s. They marched, protested, lobbied, and even went to jail. By the 1870s, women pressured Congress to vote on an amendment that would give them suffrage rights. This amendment became known as the 19th Amendment.
After decades of arguments for and against women's suffrage, Congress finally voted in favor of the 19th Amendment in 1919. This is called ratification. After Congress ratified the 19th Amendment, at least 36 states needed to vote in favor of it for it to become law.
On February 9, 1920, Idaho ratified the 19th Amendment. By August of 1920, 36 states (including Idaho) ratified the amendment, giving women the right to vote.