Could possibly be the same Dr. James Moffett of Cumberland County, NC. There are several references in the Cumberland County deeds to a Moffett family in Randolph(same family) and in Jackson, Illinois.
Dr. James Moffett mentions his brother (I believe), Dr. William H. Moffett/Maffit/Moffitt. He married Mariah Booth Winfield and moves to Marlboro, SC and dies before 1835.
William H Moffett was married to Margaret Jane Adam, daughter of Robert Adam. Rev. John Newland Moffett was his brother because Dr. William H Moffett raised his son, John Newland Moffett, Jr, whom you can find a story on in the Wikipedia. In the division of lands involving Randolph County, it mentions Charles, John, Samuel, Silas, Isaac, Hugh, Soloman, Davis Moffett also Lewis Needham and wife (Mary Moffett Needham), Lewis Gardner and wife (Rebecca Moffett Gardner), Robert Wilkenson and wife (Catherine Moffett Gardner). There is also mention of a John Moffett and wife Dolly in another deed involving a mention of Randolph County.