For me it has to be Malcom X, I'm not American, but I read his autobiography when I was young and it left a life long impression on me about justice and resiliency. He grew up in an extremely oppressive society, his dad was murdered and his mother was sent to the loony bin and he was clearly lost and traumatized. When he went to jail he was smart enough to be like what the hell, why am I here? Educating himself and channeling his energy into caring about others and justice transformed him into one of the most powerful and well respected leaders of his time.
He is often denigrated by Americans as violent and contrasted with King Jr. but by all accounts whenever he was in a position to project violence he chose de-escalation like during the Harlem riots and saved lives as there were people in the US in positions of military power who would have loved an excuse to do to them what they did to the indigenous across the entire country.
He was angry but principled and really set a template for me about how to be a leader and help me process my own anger and channel it into something more positive.
Hans and Sophie Scholl, brother-and-sister members of the White Rose resistance movement within nazi Germany, who were executed for producing a series of anti-nazi propaganda leaflets at the ages of 24 and 21 respectively. I always have a soft spot for people who use art and language to combat fascism, and Sophie in particular had a real way with words:
And her final words before being executed:
NB: I should note that there's a bit of conflict about this, as the nazi executioners were not meticulous record keepers. But it seems that it was either this or "Your heads will also roll", but either way she apparently said both and either one is great IMO.