Final answer:
Cesar Chavez advocated for migrant workers' rights and, with Dolores Huerta, co-founded the United Farm Workers union, leading to significant improvements in labor conditions after nonviolent protests and a grape boycott.
Step-by-step explanation:
Cesar Chavez is an important historical figure known for advocating for migrant workers' rights. A US citizen of Mexican origin, Chavez, along with Dolores Huerta, co-founded the United Farm Workers (UFW) union to improve the conditions and wages for farm laborers.
Chavez was instrumental in organizing nonviolent protests like strikes and a successful boycott of grapes, which eventually led California grape growers to recognize the union and improve working conditions for farm workers by 1970. His efforts were influenced by the nonviolent approaches of Mahatma Gandhi and were pivotal in the Mexican American fight for civil rights.