The Cinco de Mayo holiday dates from the Civil War era and was first
embraced in California. UCLA professor David Hayes-Bautista is the
author of "El Cinco de Mayo: An American Tradition."
According to a news release from UCLA
In the process of extracting Latino demographic data from nearly a dozen Spanish-language newspapers published in California since the 1850s, UCLA professor David Hayes-Bautista stumbled upon the answer to a question that for years had puzzled scholars and amateur historians alike: Why is Cinco de Mayo — a holiday commemorating the Mexican victory over the French at the battle of Puebla on May 5, 1862 — so widely celebrated in California and the United States, when it is scarcely observed in Mexico?
As Hayes-Bautista explains in "El Cinco de Mayo: An American Tradition" (University of California Press), his new book on the origins of the holiday, which publishes May 5, Cinco de Mayo isn't Mexican at all.
Rather, it is an American holiday, rooted in the Civil War era and commemorated today because a network of Latino groups in California known as the juntas patrióticas mejicanas (Mexican patriotic assemblies) deliberately created a public memory of it