In 1880, Campobello had a population of 99 people.
The family of Bailes Brannon had grown by 1880 and included John A (Arch?) age 14, Ella (Milly?) age 11, Pinkney age 9, Mary age 7, Martha age 4 and mother-in-law Milly Brannon age 65. No-one in the family can read or write. Bailes and Sophia's parents were all born in South Carolina. Bailes and his son John A are described as farm labourers in this Census. The family were living in Spartanburg Township. Spartanburg is 22 miles from Campobello. In 1880, the town of Spartanburg had a population of 3,253. This must have been a huge change for the family, moving from a rural area into the county seat.
I don't know what happened to the family after 1880. Maybe they migrated North? A first search through the marriage and death records for the children did not yield any likely matches. Neither could I find a death record in South Carolina for Milly, Sophia or Bailes Brannon. If you have found this family I would love to hear from you.
Original Census Records 1870 & 1880 at ancestry.com
South Carolina Death Records originals at ancestry.com
Wikipedia for local history of Campobello and Spartanburg