Barrio Boy revolves around the childhood and adolescence of a young boy named Ernesto. He and his mother live in a tiny little town in Mexico and are not rich people. Surrounded by family, Ernesto is raised by all of his aunts and uncles collectively. He's a diligent boy, working and helping out around his home in order to help his mother scrape by in life.
Everything changes for him and his family when the rurales come through the village all of a sudden. They are the Mexican secret police, who've come to draft for the impending Mexican revolution. All of Ernesto's family immediately runs away. They go to various small towns in Northern Mexico and eventually Sacramento, always moving northwards. In Sacramento, he and his mom settle into a little apartment. While there, Ernesto receives the opportunity to go to school for the first time, an experience which he relishes.
Eventually Ernesto's mom marries again. They move into a wealthier white neighborhood. In this environment Ernesto really prospers. He starts excelling in school, to the point where his parents even buy him a personal telephone.
Then his mom dies. Ernesto moves in with his uncle José. Money is not a plentiful as before, so Ernesto works multiple jobs. Convinced that his intellect was worth more, he isn't satisfied with his work. When summer rolls around, he works in a labor camp until he leaves because of their unsafe living/working conditions. He gets home to his uncle's apartment and bikes over to his old school. The book ends with Ernesto contemplating his future in regards to education and intellect.
