THWING
The Thwing family has its European roots in England. Benjamin Thwing (1619-1672) is the American progenitor for this family. Coming to Massachusetts from London, England as early as 1642, Benjamin Thwing was married to Deborah (also from London) and had seven children, all born in Massachusetts.
South Carolina Progenitor
James Thwing, III was born in Boston, Massachusetts in 1794. He is listed as a 6th generation descendant of Benjamin Thwing in "Thwing: a genealogical, biographical and historical account of the family." published in Boston, Mass. by David Clap & Son, 1883. I believe James Thwing traveled by ship from Boston to Charleston, South Carolina in the 1820s. He married Agnes Ann McLeod and they were settled near Marion, South Carolina by 1825. James Thwing was a schoolteacher and lived on a farm that bordered that of the Keeffe family during the 1840s and 50s. James and Agnes Thwing had five children: Jannett, Martha Ann, James, Harriet and Frances.
I believe in 1849 that James Thwing may have had an affair with Elizabeth Campbell Keeffe, the second wife and widow of William Keeffe. This child was given the Keeffe surname by his mother.
After James Thwing died in 1858, his wife and all of his children except Martha, moved to Texas. Martha Ann Thwing remained near Marion, SC and married Samuel A. Campbell, who was in some way related to Elizabeth Campell Keeffe.