Many particularly famous Native Americans are famous because they suit late 19th century American narratives that God intended the entire North American continent to belong to the USA. (There were secular versions of the argument, too, but they amount to the same thing.) The idea is that by valiantly trying and failing to resist American expansion, these Native Americans "proved" that it was "God's will" that America expand. Tecumseh and Sitting Bull are the most prominent examples, but Pocahontas, the Seminole Wars, Geronimo, Metacom, and others tie into this. Essentially, Americans admired them precisely because they became symbols of American Exceptionalism.