Slavery was not officially banned in some northern meetings until 1776. A Quaker's relationship to slave-owning was often colored by economics: those involved in raising tobacco or cotton may have found ways soothe their conscience by educating & kindly treating their slaves. I would imagine JAC was in this category. Did his owning a mill (grain raising being less labor intensive) mean he was attempting to evolve out of owning slaves? Yet, his heirs were surely raising cotton during the families' moves across the southern states.
I've heard that JAC was a loyalist during the Rev & this fits with James Lindley being hung by the rebels. But this loyalist biz is another complicated area.
Perhaps we should continue our conversation off-forum? That way we can hash out our differing theories on Abercrombie heritage/backlines without boring others & using up forum space. I am very interested in discussing Chrystie Abercrombie who married Martin Dial and her supposed birthdate in the 1740s, and other such things.