When it was ratified in 1920, the Nineteenth Amendment to the United States Constitution granted the right to vote to women. Before that time, some states had passed legislation allowing women to vote, beginning with Wyoming in 1869:

“An Act to Grant to the Women of Wyoming Territory the Right of Suffrage, and to Hold Office.”From General Laws, Memorials and Resolutions of the Territory of Wyoming, Passed at the First Session of the Legislative Assembly, convened at Cheyenne, October 12th, 1869 (Cheyenne, 1870; Wyo 1 1869). Law Library of Congress. full caption | bibliographic record

Be it enacted by the Council and House of Representatives of the Territory of Wyoming:

Sec. 1. That every woman of the age of twenty-one years, residing in this territory, may, at every election to be holden under the laws thereof, cast her vote. And her rights to the elective franchise and to hold office shall be the same under the election laws of the territory, as those of electors.

Sec. 2. This act shall take effect and be in force from and after its passage.

Approved, December 10th 1869.⁵⁸

Western territories such as Colorado [full item], Utah, and California followed Wyoming's example in the years from 1869 to 1911. Women gained limited suffrage rights from other states and municipalities, such as Kentucky, which gave widows with children the right to vote in school elections as early as 1838.⁵⁹

During the women's suffrage movement, New Jersey became a rallying point for the early suffragists in their demonstrations and court cases. Interestingly, New Jersey had given women who met the enumerated requirements the right to vote in its 1776 constitution:

IV. That all inhabitants of this Colony, of full age, who are worth fifty pounds proclamation money, clear estate in the same, and have resided within the county in which they claim a vote for twelve months immediately preceding the election, shall be entitled to vote for Representatives in Council and Assembly; and also for all other public officers, that shall be elected by the people of the county at large.⁶⁰

Sixty-four years later, however, the state constitution of 1844 took away those suffrage rights, regardless of a woman's standing, stating that “One. Every white male citizen of the United States, of the age of twenty-one years, who shall have been a resident of this State one year . . . .” would be entitled to vote.⁶¹

Minor v. Happersett, 1875. Law Library of Congress. full item

To force the issue of national suffrage, women filed court cases. The case of United States v. Susan B. Anthony was highly publicized.⁶² When Susan B. Anthony (1820-1906) tried to vote in New York for a member of Congress in 1872, the United States brought criminal charges against her. The court found Anthony guilty and fined her $100 plus court costs. That same year, Mrs. Virginia Minor (1824-1894), a Missourian, attempted to register to vote, despite a Missouri statute limiting voting rights to the “male citizen of the United States.” Eventually, the U.S. Supreme Court heard Minor's case and decided in favor of the state: “Being unanimously of the opinion that the Constitution of the United States does not confer the right of suffrage upon any one, and that the constitutions and laws of the several States which commit that important trust to men alone are not necessarily void, we Affirm the Judgment.”⁶³ Because the various state laws on voting rights were arbitrary, it was necessary for the suffragists to mount a national effort for securing the franchise. The Nineteenth Amendment gave women some leverage in the electoral process.