Do you know what Cinco de Mayo really commemmorates? Contrary to popular belief, Cinco de Mayo (the fifth of May) is not Independence Day for the United States of Mexico. That occurs on September 16th. A Huffington Post report: According to David Hayes-Bautista, a professor of medicine and health services at UCLA and author of the newly released "El Cinco de Mayo: An American Tradition," the holiday's history in the U.S. goes back to the Gold Rush when thousands of immigrants from Mexico, Central and South America came to California during the Civil War. Latino immigrants were concerned about the Union's lack of progress and Napoleon III's interests in helping the South (preservation of slavery). When Latino's defeated the French at the Battle of Puebla, the win served as a sign that their side could win. In the years that followed, Latinos in California and the U.S. Northwest celebrated Cinco de Mayo with parades of people dressed in Civil War uniforms and gave speeches about the significance of the Battle of Puebla in the larger struggle for freedom. Over the succeeding decades, the celebration of Cinco de Mayo moved into Mexico and other areas. Today, let's remember its origins and the part Latinos played in the abolition-of-slavery movement.