Yes, the military should be ashamed about their actions. In the 1890s, blankets and some goods would mean nothing to the US military. I am sure they could have worked out a deal like "we will give you this now, and acquire the rest + a bit extra in a month or 2".
Check out The Terror (2018), a 10-episode suspense-horror set in the 1800s telling a fictional story with similar themes, but with the tables turned on the colonizers. I recommend it for anyone who found this topic interesting.
There is also an antagonist in Neal Stephenson's Snow Crash (1992) who came to mind, Raven. This character is an Aleutean Native, an ethnicity that falls under both Alaska and Russia territory. The history described in this article also reminds me of his story.