What is the purpose to the introduction in "the way to rainy mountain"? to entertain the read with personal ancedotes to convince the reader to read more about the kiowa tribe to present an argument regarding the importance of the text to give background historical information regarding the book

I believe the answer is  To give background historical information regarding the book
Giving the background of the historial information will make the readers understand the entry point of the book, which tell a story about the hardship that is faced by Aho which was born at the last moment of Great times in Kiowa's history.

Explanation:

Hi Brother ! It's your sister here ! My day's going boring but you've made it wonderful. Oh okay , if you're saying that , so I'm smiling right now. Yeah, I've drank water and I want you to also drink water. Yeah, I'm negative (otherwise I'm positive) just to see that how you're gonna tell Mom , lol ! Hope your mom also gives you love and affection and I also hope that you have a nice day ! Bye brother ! Will meet soon ! : ))