The Nineteenth Amendment to the US Constitution was enacted in 1920, and it prohibited exercising discrimination or denying any US citizen the right to vote due to gender reasons.
It was adopted as the resolution to the suffrage movement that had been conducted by women both at the state and federal levels. In the 1910s many states did not allow women to vote. Until the issuing of this amendment, a decision of the Supreme Court had definitely stated that the Fourteenth Amendment had not granted women the right to vote.