(The Hispanic Society Museum in West Harlem has an excellent collection of paintings that portray different castas and their names. Among many writers, off the top of my head, I recall María Teresa Babin's book on how these ideas influenced Puerto Ricans' conception of race and classifications; José Vasconcelos value system gave the mestizaje a cuasi religious absolutism; Sarmiento and others in South América promoted the "blanqueaminto" of their countries; and as recently as this past decade, intellectuals and political leaders in one half of an island are using these constructs to argue against letting the other half to be mixed with its citizens. This is one topic missing from most Multicultural Education courses in the USA, as they are controlled by people who know nothing about such an influential force in Latinamerican's identities formulation)
Anyway, for the Latinamericans, perhaps It all began with the Mozarabes or Hebreos in El Andaluz or with the Guanches in the Canarias confronting the invaders and losing control of the lands, but not losing track of the identity of the invaders: the Godos (Goths). Six hundred years later the islanders still refer to their fellow citizens in the rest of Spain as the "Godos", the Goths.
These are all historical events and peoples that serve to explain the ephemeral qualities of national identities, as opposed to the need to name our social groups, a constant in human categories. The invaders did not come as Spaniards as we understand the concept today but as "súbditos del Reino". It was the identity of the Reino what linked these groups at an earlier time and not the nation since it is not after the "reconquista" that such a concept came about.
As a teacher at CCNY I came across quite a few Latino and Latin American students (including a few professors also) who were not aware that their entrenched national identities were the product of recent historical events. When asked to explain when their identities were originally formed, under what political and historical conditions they were unable to do so. Some became quite defensive (¡qué pasa, viejo!) as if offended by such question. And when told that as early as 200 hundred years ago many of them would have not been considered a citizen to vote (read Fernando Picó on the founding of Cayey, a mountain town in Puerto Rico to get an idea as to was considered a citizen during the Spanish colonial regime) and the reasons for such policy, they were on route to reshape histories, theirs and the students sitting nex to them. ("Y tú aguela dónde está" wrote Fortunato Vizcarrondo).
With regards to criollos, when asked about this very Latin American identity, "nada de nada", neither most students nor quite a few bilingual education professors knew the history of its conception, much less how a 19th Century Criollo would react if told who is considered a criollo today.
(No bibliography on this important subject is included: sorry no more freebies since I decided not to be used by my CUNY colleagues who then are so racist or homophobic as to tell my stundents that an European intellectual is more important than my ideas, y al que no le gusta el caldo, se le dan dos tazas)