>>>Well, portuguese have been around there for a long time (see http://www.loc.gov/rr/hispanic/portam/cabrilho.html - what would you know, this is under the "Hispanic Division"!).
>>>
>>Interesting and so typical of history!
>>
>>“On September 28, 1542, Juan Rodríguez Cabrillo landed at San Diego Bay”.
>>
>>I enjoyed the spelling of his name in the reference you gave me - João Rodrigues Cabrilho. As is so typical of history things become distorted. I would like to know why we were taught the Castellano spelling? He is a very famous person in California History. We even have streets named after him - with the Castellano spelling.
>
>To be honest, Juan Rodríguez Cabrillo is closer to ancient portuguese spelling: in 17th-18th century portuguese (I'm not at ease with previous periods) the most common spelling would be something like Joam Rodriguez Cabrillo. The use of the tilde to nasalize phonemes is a modern solution.

Could there have been a less clear separation between Spanish and Portuguese back then? Was there greater use of dialects that were somewhere in between, such as Galician?

I looked at a Galician dictionary in a bookstore and couldn't decide how different it looked from Spanish or Portuguese, especially since I don't know either. To me the spelling of the words looked more like Spanish, which makes sense since Galicia is in Spain.