What did the 15th Amendment guarantee? Why were women disappointed by this amendment?

 In 1870, the 15th Amendment to the Constitution was ratified by the states. This amendment stated that:

"The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of race, color, or previous condition of servitude."

This amendment enshrined black men's right to vote in the law of the land. Notably, however, it omitted women. American women had played an important role in the crusade against slavery for decades, and had launched the women's rights movement in the 1840s. Advocates of women's rights had hoped that the results of the Civil War would extend the vote to women, as well as black men. In 1869, in response to their recognition that the 14th and 15th Amendments would extend voting rights to black men, but not to women, women's rights advocates founded both the American Women's Suffrage Association and the National Women's Suffrage Association.