Who is Iacoomis, Joel from Caleb's Crossing: A Novel and what is their importance?

Iacoomis is a member of the Wampanoag, one of the tribe's earliest converts to Christianity, and endures taunting and a degree of rejection from some of its other members, many of whom eventually follow his lead. Joel is Iacoomis' son, and one of the first young members of the Wampanoag community to take schooling in Christian teaching. He and Caleb become both classmates and close friends, with Joel eventually surpassing Caleb in both quality and quantity of learning. Joel is tragically killed in the narrative's final chapters, attacked by natives resentful of his having given so much of himself over to the white man and his faith.