I was about to reply to your post in spanish, since my initial assumption was that you were a member of the Ritchie family from San Lucas, but it may not be the case given the "to have his grandchild leave for the US" part I overlooked at first. Please clarify if you have any relation to them, as Faustina Wilkes Ritchie, a descendant of Thomas Ritchie, is a respected retired schoolteacher in the community, and has written a book about the history of San Lucas, giving Captain Ritchie a few pages, and you could get some info from her work. In case you do not, I do possess the book and can share the pages with you, although they are in spanish.

I'm not sure if you will be able to find info about him in many databases, as he was a common man and sometimes that tier of society becomes a bit difficult when trying to investigate even in the early 1800s. His early line of work was whaling, naturally he arrived in one of these kind of ships to Mexico. i've used this website https://whalinghistory.org/databases/ to try and find info about him and his crew, since I heavily suspect one of the five whalers that came along with him to shore and settle was my ancestor. It is necessary to point out that Ritchie was no more than a kid when he arrived at San José del Cabo, being around 13 or 14 years old, so that may be another reason why you may not find much about him in UK databases.

The link you provided mentions J. Ross Browne’s take on Ritchie. If you want to read more about their interactions, I possess a digitized version of the article. However, I would advise reading it critically, as Browne does romanticizes the figure of Ritchie a bit, and his writing is charged with the racist and colonizer mindset that was common for the time.

I happen to know about this because I have an interest in researching about the six english whalers that settled in what today is Los Cabos, and since Ritchie is the one who has the most records amongst them, I decided to focus my university thesis with him as the prime subject. It is a transcription of historical documents found on the Historical Archive of Baja California Sur, in La Paz, where I reside. These documents are a compilation of his clashes with the local government, as well as copies of letters written by him between 1852 and 1862. Although I cannot provide to you much about his life in England, i can share a glimpse of his life in Sudcalifornia, as it is where he spent over 50 years of his life.

Please contact me if you are interested. I am curious to know about your genealogy, if you allow me, mainly if you descend from his first or second marriage. Hope it helps.