There are a handful of main characters in Ernesto Galarza's 1971 memoir Barrio Boy.

Ernesto

The memoir begins in Mexico with Ernesto living with his single mother, a seamstress. He is roughly 4 years old then. As the narrative progresses, Ernesto and his mother are forced to move several times in order to avoid the fighting of the Mexican Revolution (1910 through the early 1920s). They eventually move to the United States—first living in Tuscon and then in Sacramento. It's while they are in Sacramento that Ernesto first lives in the barrio, the Spanish word for neighborhood and a term that others use to denigrate Mexican immigrants.

Ernesto's mother
Doña Henriqueta is a single mother. When the reader is first introduced to her, she and Ernesto are living in a hand-made adobe house in rural Mexico. A seamstress, she works very hard day and night to ensure that Ernesto is well cared for and never hungry. One of Ernesto's favorite memories, he recalls, is making tamales with his mother. Doña eventually teaches Ernesto to read and encourages him to get an education. When they move to Sacramento, Doña meets another Mexican immigrant and remarries. She has two children with her new husband, which Ernesto reflects on fondly. However, she suddenly dies from influenza, resulting in Ernesto moving in with his uncle José.

Ernesto's uncles José and Gustavo Galarza
Both of Ernesto's uncles are very loving and supportive. Both are brothers of Doña Henriqueta. Some time after the family moves to Sacramento, Gustavo passes away from influenza, as well does Doña. This tragedy results in José agreeing to let Ernesto live with him in the barrio, provided that Ernesto continues to go to school and takes care of those expenses.