Before 1920, Voting Rights Differed Across State Lines.
Suffrage laws varied considerably in January 1919. 15 states allowed women to vote in all elections, while 21 states barred them from certain contests. ( i.e. women in Texas could only cast ballots during primaries). Only 12 states that remained prohibited women voting altogether.
The 19th Amendment to the U.S. Constitution is ratified in 1920, giving women the right to vote nationwide.
8 Days after the 19th amendment took effect, 10 million women joined the electorate. Evidently, showing the sheer volume of brand new voters created by this legal action.
“Interchange: Women’s Suffrage, the Nineteenth Amendment, and the Right to Vote.” Journal of American History, vol. 106, no. 3, Dec. 2019, pp. 662–694. EBSCOhost, doi:10.1093/jahist/jaz506.