The Question and Answer section for Last of the Mohicans is a great resource to ask questions, find answers, and discuss the novel.
Cora begins to feel nervous that Magua intends some great danger to them. She asks that he purchase wealth by Alice's safety and pour out his malice upon her. Magua's price: that Cora herself consent to be his wife and live in his wigwam.
Cora belongs to Magua because he has taken and laid claim to her..... he doesn't need another reason. She is his captive.
A lot of them are killed or had their farms burned.