Muchas gracias *Sandra*
Feliz año nuevo a ti también
This is what I know about them:
José Ventura de Ben (Ventura is the correct spelling, it appears as Bentura in his father's will in 1851, but he's called Jose in the other documents I've seen on pilot.familysearch.com) was born I think around 1797-1799; his parents married in 1796, I know that for a fact, and he was their firstborn. In the US 1850 census he is listed as being 51 so c. 1799.
In the same census of 1850, Francis (or Francisco) de Ben and Manuel de Ben (presumably his sons) are living with him, and they are 25 and 18 respectively. I've found Manuel Deben (slight alteration of the last name) being 34 roughly in 1865, when he took part in the American Civil War, on the Confederate side. I haven't found out if he died during the war, I don't think he did. His cousin José Antonio de Ben (emigrated in 1860) also took part in the war.
Both Francis and Manuel were born in Spain, which would indicate that they emigrated sometime between 1830 and 1850. I have no idea about their mother or if they had other siblings. Their christening records are kept in Santiago de Compostela, where I'm going in a month. I'll probably be able to find who their mother was, but any more details about them in America (when they died, when José [Ventura] de Ben died, what they did for a living after the war...).
Thank you so much!