The Far Away Brothers, by Lauren Markham, is recommended for older audiences, although some sophisticated and higher-level readers in 8th grade may tackle it with parental permission (there's mention of drugs, drinking, sex, murder, rape and other violence).
It is a moving story of Ernesto and Raul Flores, who migrate from rural El Salvador to escape the brutal MS-13 gang and a vengeful Uncle bent on killing one of the boys. It's about their flight across the border, at different times, and their struggles once they reach the US and live with an older brother in Oakland. In a world where money is life -- not just for them, but for their family in El Salvador -- often their education must take a backseat. Their storyteller, Lauren Markham, notes she's their teacher and she chronicles their challenges and trials.
Markham includes an excellent explanation of our nation's immigration policies and the history behind them, dating back to the 1951 drafting of the Refugee Convention.
Her message is bleak and the ending is less than satisfactory -- you never find out what happens to the Flores' older sister, who you last see afraid to go outside, after the boys leave and the family sells its land to pay the debt of the brothers' crossing.
The publisher offers an excellent teaching guide correlated to Freshman year standards, as well. I know our English teachers struggle to find / teach culturally relevant resources with well-developed teaching materials, and 21 discussion questions go with this book. To effectively teach this book, there are synthesis and analysis writing prompts, a before reading hook, and other activities from the 11th / 12th grade teaching guide, also provided by the publisher. The topic would make an excellent candidate for a freshman year research paper, as well.
It would be a great accompaniment to a 9th grade AP Human Geography curriculum as an excellent example of an in-depth look at push-pull factors on immigration.