Have you checked out the Bertie Co. Court Records? Since Horatio was 16 yrs old in 1850, it is likely he was serving an apprenticeship, and there would be a record of that. Sometimes, not always, the apprenticeship records would include the names of parents, and other court records may have additional info. Often, court records are the only place you will find mention of free people of color prior to 1850, since many may have been living with someone else as head of household, and most FCP were required to be bonded out while they were children. Most Court records, including Apprenticeship Bonds, are on microfilm and are available at the State Archives, or through your local Family History Centers. The link below has a listing of what records are available and where, and I strongly urge you to visit a FHC to do some research on your family.