Well, you learn something new every day:
In the United States, Cinco de Mayo has taken on a significance beyond that in Mexico. The date is perhaps best recognized in the United States as a date to celebrate the culture and experiences of Americans of Mexican ancestry, much as St. Patrick's Day, Oktoberfest, and the Chinese New Year are used to celebrate those of Irish, German, and Chinese ancestry, respectively. Similar to those holidays, Cinco de Mayo is observed by many Americans regardless of ethnic origin. Celebrations tend to draw both from traditional Mexican symbols, such as the Vírgen de Guadalupe, and from prominent figures of Mexican descent in the United States, such as César Chávez.
To celebrate, many display Cinco de Mayo banners while school districts hold special events to educate pupils about its historical significance. Special events and celebrations highlight Mexican culture, especially in its music and regional dancing. Examples include ballet folklórico and mariachi demonstrations held annually at the Plaza del Pueblo de Los Angeles, near Olvera Street. Commercial interests in the United States have capitalized on the celebration, advertising Mexican products and services, with an emphasis on beverages, foods, and music.
As for me, I'm doing what any self-respecting gringa does on Cinco de Mayo: going to Chipotle for lunch. Normally, I might go to Taco Bell, but this being a holiday and all...