Before the 19th Amendment was ratified in 1920, a women’s right to vote depended on what state she lived in.
This 1919 map from the National Woman Suffrage Publishing Co., shows the patchwork of laws passed by male-controlled state legislatures that existed before the 19th Amendment. As of January that year, there were only 15 states with full suffrage, 20 where women could vote in some but not all elections, and 12 where they couldn’t vote at all.
The Western U.S. led the country in giving women voting rights. Wyoming, then a territory, was the first in 1869. Utah Territory followed in 1870, although an act of Congress in 1887 reversed that. Full women’s suffrage was passed in Colorado in 1893 and in Idaho in 1896.
The first woman to serve in Congress was Jeannette Rankin, a Montana Republican who served in the House from 1917 to 1919 and again in 1941 to 1943.