In 1886, Martha Washington was on the $1. I believe she was the only actual historical women to be depicted as the main figure on US paper money.
Pocahontas was on the 1896-1878 $10, but it was an allegorical representation.
There were some women on the $100 in 1880 though I'm not sure who they are (or if they were real people).
The Educational Series of notes contained images of women (though as allegorical figures). The $500 had a a picture of allegorical Justice depicted as a woman.
The $10 at one point had topless women on it (again, allegorical).
US paper money used to be far more interesting.