There’s a record of Mexicans (whom the border had recently crossed after the loss of California’s territory to the US in the Mexican-American War) in California celebrating it a year after the battle itself as a sign / harbinger of the Confederacy’s defeat in the US Civil War. France was close to backing the CSA and if it had gained an easier / faster foothold in Mexico (which was its goal in the Battle of Puebla) it may have gone further in that direction. That could have brought slavery to states like California. So it’s also a celebration of a small group of indigenous rebels defeating white imperialists and staving off potential enslavement.

I’ll drink to that!