When did all women get the right to vote?

Why this is the answer

Women across the country won the vote in 1920, when the 19th Amendment became part of the Constitution. Its rule is short: neither the United States nor any state may deny or abridge a citizen's right to vote because of sex. Congress passed the amendment on June 4, 1919. It was ratified on August 18, 1920, when Tennessee became the 36th state to approve it, reaching the three-fourths of the states that an amendment needs. That timing explains the second accepted answer, "after World War I." The war ended on November 11, 1918, and the amendment followed in less than two years. The road there was long. A women's suffrage amendment was first introduced in Congress in 1878. For decades supporters organized, petitioned and picketed, and some went on hunger strikes. Some worked state by state instead, and by 1912 nine western states had already given women the vote under their own laws. Susan B. Anthony, known for campaigning for the right of women to vote, died 14 years before ratification, yet the amendment was still widely called the Susan B. Anthony Amendment. Any of the three official answers works: 1920, after World War I, or the 19th Amendment. A handy link is that the amendment's number matches the first two digits of the year, 19 and 1920. The easy mistake is to mix this up with the earlier amendment about men. The 15th Amendment, ratified in 1870, protected the vote for male citizens of any race. So "1870" and "the 15th Amendment" belong to that earlier step and are wrong here. It also helps to read the word "all" with care. Ratification did not open the polls to every woman in practice. The National Archives notes that many women were kept from voting long into the 20th century by discriminatory state laws. For the test, though, the year that counts is 1920.