Upvote:3
Your question is an interesting one, but difficult to ascertain. It is estimated that around 8% of the Spanish population are descended from nobility, but this does not mean that they all held titles like those of Duke or Marquis; for a large percentage of nobility in regions like Pais Vasco, Navarra and Cantabria were untitled nobility or Hidalgos (the equivalent of Esquire or Knight, depending on the interpretation of the author who does the translation).
Under this assumption (which has not been studied much), the percentage of Spanish “nobility” migrating to the Western Hemisphere would be greater than assumed. These Hidalgos were not wealthy but their nobility exempted them from paying taxes, though they worked as laborers or farmhands without losing their nobility.
This changed in 1836 in Spain when the Constitution prohibited all the benefits Hidalguía carried with it, and in Latin America when the former Spanish colonies adopted Republican constitutions that made public displays of a family’s nobility useless. Mexico expelled all Spaniards in 1827 & 1833. The exiles left for Cuba (a Spanish colony until 1898) or Spain, which also made the territory unwelcome for Spaniards (and Spanish nobility) until the 1870s.
If you want to know about titled nobles that settled in Mexico after the independence, it would be hard to find much information on that, though you could look in to Madame Calderon de la Barca’s memoir of her stay in Mexico as the wife of the Spanish ambassador.
In the city where I live (Puebla, Mexico), there are still two or three families that claim nobility extending to the colonial period (1521-1821); there are however people who descend from Basques or Cantabrians who arrived in the 19th century who can claim descent from nobility through their hidalgo ancestors.
Here are links to some works on hidalguía in Spain and the Western Hemisphere:
La Hidalguía en el Pueblo Cantabro
Peruvian Hidalgos before independence