He, along with his younger sister Katara, discovers an Airbender named Aang, the long-lost Avatar, and accompanies him to defeat the imperialistic Fire Nation and bring peace to the war-torn nations.
He subsequently bowed to Aang alongside his sister and the entire Northern Water Tribe.
The only difference is federal recognition happened decades ago, which if anything should have you more skeptical considering that active efforts to ethnically cleanse Native Americans were ongoing when the federally recognized tribes were drawn up.
Those people certainly exist.
He would also leave stories, drawings and advice for Aang and Katara's son Tenzin, perfectly playing the role of the fun but responsible uncle.
And I also wanted to work on my graphic skills.