TRIGGER WARNINGS:
This chapter is how Patrick enlisted in WWII. The recruiters are especially interested in potential code talkers, which makes them interested in Patrick when they hear he knows Dakota and Lakota. Patrick, in turn, is not shy about pointing out the hypocrisy of the US government trying to "beat the languages out of me" and successfully "whipping it out of [my mother]," only to turn around and ask them to use those very languages to help them win the war.
He doesn't get explicit, but he does talk about his very unpleasant months in boarding school, so child abuse, institutional racism, etc.
But here's a more fun historical fact: in WWI and WWII, something like 30% of all Native American men--particularly Plains Indians--enlisted. The highest percentage of any demographic. Think about that. Imagine if 1/3 of all the men you knew aged 18 - 40 went off to fight a world war. Some of them even crossed the border to Canada years before the US entered WWI so they could enlist as a foreigner.
WWI is where Native American code talkers officially got started. The Germans noticed, and in the lead-up to WWII, some German spies went onto reservations to try to discourage Natives from enlisting, pointing out the laundry-list of crap the United States had done to them. It didn't work, and the US military--also learning from the last war--expanded the code talker program to include more Native languages.
I couldn't find a natural way to fit all this information in there, but there are snippets. Patrick later tells Janine that a bunch of his Native family fought in the last war, one of them getting a French Medal of Honor for his service. (He was ineligible to receive any such medals from the American government, as Native Americans were not citizens until 1924 except under certain circumstances.) One family member enlisted under-age explicitly to escape boarding school, although again, I haven't found a way to naturally bring up that specific detail.
Ah, well. It's a first draft. The details will either make their way in, or they won't.