Our exposure to tragic imagery in photography has reached a stage of exposure and jadedness now, whether it's holocaust, lynchings, vietnam, wounded knee dead, etc; that the subjects are dehumanized, made objects, memes, and are deprived of all dignity.

A quick search on 'Sitting Bull" reveals this: ancestral images are canvasses to place whatever narrative you want: the photo, though an image, creates a domain to invent whatever you desire, to take possession, claim, and invent a voice.

Her Holy Door, Sitting Bull's mother, seated left; Sitting Bull in centre and his eldest daughter, Many Horses, with her son on her lap. Uncropped. 1883

[William Cody Archives]

This man had his own name. His own words. His own life beyond the moment to take this image or throw words on top of it.

Copyright laws vary by nation, but in general photographs pre-1920s are generally public domain, meaning anyone can do, basically, whatever they want with it. Photos of Indigenous subjects, say late 1800s, are therefore fodder for memes, commercial uses such a t-shirts, with no

...legal recourse.

The most important lesson is every single person in any of these photos has living descendants, kin, and a legacy, today. Respect that as you would respect your own photos.