For a history of Native American depictions in movies, I recommend the 2009 documentary Reel Injun.
As a kid, the first exposure I got to Native Americans and Hispanics was on kid westerns like Roy Rodgers and Lone Ranger. Minorities were almost always treated sympathetically, as poor-but-honest people being threatened by evil bankers, cattle rustlers, etc. Many years later I decided those stories were allegories for the Civil Rights struggles of the 1950s, that prime time TV dramas weren’t allowed to touch.