Who were the women on the US gold dollar?

Answer 1

There were only 2 series of gold $1 coins. Those minted from 1849 to 1854 have a picture of Miss Liberty, while those made from 1854 to 1889 have a stylized Native American princess*

Some modern "golden" dollars carry a portrait of Sacajawea.

(*) The image may have been intended as a blend of both Miss Liberty and a Native American woman, akin to the design on the famous Indian Head cent.