Here is a brief and very general overview, by state, of the various branches of the family and who founded each branch:
VA: most VA Avents seem to be descended from Col. Thomas' son John Avent, especially those who still live in Southside VA (the area south of the James River). One of the main branches seems to go as follows: Col. Thomas/Elizabeth => John Avent/Margaret => William Avent => Samuel Avent/Jenny Woodruff => Tamlin Avent/Sarah Dupree......
NC: most NC Avents are descended from Col. Thomas' sons William and Peter. William's descendants formed the Chatham Co., NC, Lee Co., NC and Nash Co. branches, while Peter's descendants formed the Harnett and Cumberland Co. branches
TN: the oldest Avent branches in TN seem to descend from Peter or James Avent, who were sons of John Avent and Elizabeth Grizzard. This John Avent was the son of John Avent (wife Margaret) who was in turn the son of Col. Thomas Avent.
SC: most SC Avent and Avant families seem to have originated in NC, though there are Avant genealogists who claim that they descend from Huguenots named Avant, and who were not apparently related to Col. Thomas Avent at all. The webmaster has never seen any hard evidence backing up this belief, however. (That is not to say that such hard evidence does not exist, though.)
FL: most FL Avents and Avants descend from the GA branch.
AL: there is not much of a pattern to the AL Avents, though many of the early AL Avents migrated there from GA. There is also a branch that is descended from Joseph Carson Avent (1830-1904) and wife Mary E. Douglas. Joseph Carson Avent was a Methodist minister and politician who moved from Chatham Co., NC, to Arkansas around 1853, and then moved to Pollard, Escambia Co., AL.
MS: MS and NC seem to have the largest number of Avent families. The MS branch seems to have originated mainly from a Peter Avent, who was born in NC or VA between 1750 and 1760 and died in Talbot Co., GA between 1834 and 1840. It is unclear where this Peter fits into the Avent family tree, though the webmaster's belief is that he was likely a descendant of Col. Thomas' son Peter, who lived in Cumberland Co., NC in the 1760's-70's. This Peter had five sons (William, Isham, Joseph, John and Thomas), one of whom was likely the father of the Peter Avent in Talbot Co., GA. This Peter Avent had at least two sons, William R. Avent (1802- abt 1870) and Benjamin Edward Avent (1799-1879). The largest branch of MS Avents seems to be in Lafayette Co., MS, and this branch descends mainly from Benjamin Edward Avent.
TX and AR: Avent/Avant families in these states seem to have originated mainly from MS Avent/Avant families.
The chart below gives a quick overview of where the sons of Col. Thomas Avent went: