This message is more then ten years old, but I wanted to answer.
Milo Bolling Abercrombie is the son of Leonard Abercrombie (1779-1832) and Sallie Comer (1786-1848), daughter of John Anderson Comer and Nancy Ann Burford.
Leonard's parents were Charles Abercrombie (1742-1819) and Dicey Edwina Malinda Booth (1751-1819), daughter of John Booth and Ruth Anderson.
Robert Abercrombie (1715-1779) was indeed the father of Charles and another son, Robert Jr. Both reached rank in the Revolutionary War.
Note on Robert Abercrombie: I've seen 90% of people with treesclaim that Robert Abercrombie is the son of James Abercrombie, 2nd Baronet of Birkenbog. This is not valid information. The Baronet did have two sons named Robert, but one died young and the other followed his father in baronetcy in Scotland. Source:http://thepeerage.com/p3072.htm#i30720