This is not my direct line, but your Harriet Talitha (thank heavens for a cool middle name) is a sibling to my line of William Young Robb (1844-1871).Assuming you are still searching.
I have that your Harriet was born 29 Aug 1838 in Marion Co, IL. She died 1928. She married John R Dew 2 Apr 1857 in Marion County, IL.
NOTE: In Ancestry:
Illinois Marriages, 1851-1900 about John R. Dew
Name: John R. Dew
Spouse Name: Harriet L. Robb
Marriage Date: Apr 02, 1857
Marriage County: Marion
Comments: This record can be found at the County Court Records, Film # 1010515 - 1019518.
1870 census, Illinois, Marion County, Kinmundy, District 110, 4 & 5 June 1870
Dew,Harriet, 41, widowed, keeps house, b IL, father b TN, mother b VA
Lucy J, 21, daughter, single, teacher, b IL, parents b IL
Charles F, 17, son, single, farmhand,b IL, parents b IL
Frank E, 12, son, at home b KS, parents b IL
John W, 10, son, at home, b KS, parents b IL
Edward E, 7, son, at home, b KS, parents b IL
Martha V, 5, daughter, at home, b KS, parents b IL
Herbert A, 3, son, at home, b KS, parents b IL
Scott W Foster, 33, farm hand,b IL, parents b GA
I do have information back from Harriet.Perhaps you want to email me off line I can send more. Briefly:
Her father:James Eli Robb (1807-1854) who was married to Martha Ann Young (1805-1888).Lots more back from Martha.
On the Robbs, not so much further back. This is my mother's maiden name and it really bugs My cousin and I that we cannot find much further back. We think James Eli's father was Joseph Eli Robb (1781-1861).We are not sure who he married. We think she might be a Whiteside, but nothing confirmed as yet.
So, hope this helps.As you find more on the Robbs especially, hope you will share.
We THINK the origin of these Robbs in the US (and the Carolinas) might come from the Jacobite prisoners sent over on ship Sussanah 1716 referenced elsewhere in Genforum.Just cannot connect any dots between our Joseph Eli and one of these Robb men.
Feel free to email.