The Fifteenth Amendment and Women's Suffrage

I'm writing a paper on the constitutional arguments for women's suffrage during Reconstruction. One interesting move that the advocates made was to say that the Fifteenth Amendment conferred or recognized a general right to vote. The argument went something like this:

1. The Fifteenth Amendment begins by acknowledging: "The right of citizens of the United States to vote."
2. Women are citizens of the United States.
3. States may regulate but may not extinguish a national right.
4. Therefore, women have some constitutional right to vote.

Victoria Woodhull also argued that women fell under the Fifteenth Amendment's language barring states from denying the right to vote on the basis of "previous condition of servitude" because women were previously held in servitude. I'm not saying that these arguments were right, but I don't think they resurfaced after 1871.