I thought the term Latin America was coined by Napoleon to empahasize that the region spoke a Romance language (Spanish, Portuguese and French are all Romance languages) as opposed to the mainly anglo roots of North America, and he knew the term Franco America would not be accepted. Napoleon was attempting to take over this region.
I guess the Cinco de Mayo reference has to do with the fact that the Mexicans defeated Napoleon.
Am I right?
I don't think Latino/Latina or Hispanic are races anymore than North American is a race - the region is highly mixed with African, European, Asian and aboriginal blood. It has always been understood primarily as a linguistic/cultural category to my mind. However, there are many commonalities between people from Latin American countries (and also many differences - like Africa, it is a huge, diverse region) and I think most people have a stereotype of what a Latino looks like. For me, I will sometimes say I am mixed race Latina/African because in my mind they are two separate things, though both parents are from the Caribbean which is in L. America.