Irish Sugar Slaves of Barbados
I can remember in my youth a caste system among blacks in which lighter-skinned folks had social advantages. Many "light" folks had formed clubs and associations in the post-Civil War era and many strived to intermarry with one another through these associations. In the 60s you could still hear fair-complected blacks citing their West indes backgrounds as being a source of social or cosmetic refinement, in many cases completely unaware of the history of the area.
And 3) let's not discount the possibility of voluntary sexual behavior between whites and blacks throughout the history of the U.S., whether the individuals were enslaved or free. An early and highly influential president of Georgetown University (Patrick Healy, S.J., 1830-1910) was part black and in fact was born into slavery. His Irish-American father voluntarily made a common-law love marriage with a light-skinned slave woman whom he had originally purchased to work on his property, but they lived together as a couple all their adult lives. They cherished their many children and sent them North to obtain good educations. Healy and several of his brothers earned PhD's and held high positions, and two of his sisters became nuns.
Fascinating, thanks!