There is a good chance the English ancestor was called Samuel Gross born 1606 in Truro Cornwall England, or his son John Gross,who died in 1658. Samuel Gross senior born 1580 in Great Yarmouth Norfolk, England was a major ship owner in England and his ships founded the colonies of Massachussetts, Maryland and Virginia. He is my direct ancestor. His eldest son Samuel Gross junior took over his father's shipping business in Cornwall in 1627. Samuel moved the money and the ships offshore during the English Civil War, and we think he settled in Barbados, but Maryland is also a possibility, as there are white Gross families from Maryland who match me on DNA. He definitely brought his ships into Baltimore.
My ancestors include West Africans and I have DNA matches to almost pure tribal folk who still live in Lagos.
I have followed the trail of a slave cartel which included Portuguese and English ships operating out of Lagos. They went to the Caribbean islands especially Barbados before bringing the slaves on to the USA.
I also have DNA matches to African Americans named Lewis and Williams. These are names associated with the slaving cartel . Have you come across anyone with the names Phillips, Lewis,Jones,Morgan or Williams in Maryland, as this might give you a clue to the origins of the African American Gross family?
There is also a possibility that the Gross ancestor fathered children in Barbados. The descendants were then brought to the USA. The other English Gross families who settled in Massachussetts and Maryland didn't seem to own any land, but worked for other plantation owners. These white servants have indenture records. The ones who worked in USA also travelled to Barbados,where they were often paid a bonus if they fathered children with an African lady. There are records for John Gross and Edmund Gross from England who worked in Barbados around 1660.
So what I am saying is the African American Gross famiy might have already been mixed race before they were brought to Maryland from Barbados.
The dates they arrived in Maryland would be between 1627-1660. If anyone decides to do their DNA the Y chromosome marker for the Gross family is R1b1a2. I am on 23and me and Gedmatch so you could always see if you match me and my cousins (and the guys from West Africa).