Here's what I know - it may or may not be connected to you:
Stephen Knowles (census data shows b. about 1800) and David Knowles (born a couple of years earlier) appear to have been children of John Knowles of Sampson county.It appears that John was married twice; his will (1802, probated Sampson co. court, 1804) leaves property to five children (all daughters) who were married and five sons who were still living at home. He lists David next to last (not that that's final proof of anything but may be a marker) and Stephen last in the will.
In about 1807, David and Stephen Knowles were listed as orphans and wards of the court and were apprenticed to learn wheelwright and carpentry trades with craftsmen named Merritt and James in Duplin county, NC.(The Knowles families seem to have lived in the area between Delway and Taylor's Bridge, sometimes called Six Runs, in what is not Sampson county but some parts of this area of Sampson were designated Duplin county off and on in the early 1800's.Sampson was broken off from Duplin about 1790 but the borders were unclear for decades so I think that that doesn't show that Stephen and David were away from the ancestral homes in 1807.)
The next record that I have for Stephen Knowles is 1825 when he marries Sarah Matilda Denmark from Kenansville, NC. In 1829, their son John was born and in 1832, their son David J was born.(I am descended from David J Knowles - I cannot find any documentary evidence of what the J in David J Knowles's name stands for but oral family tradition is that it was James.)
Family history is that David (b. about 1798), brother of Stephen moved to southern Georgia as a young man; therefore, there could easily be a Florida connection.Oral tradition is also that David and Stephen remained close, exchanging letters and visits all their lives.
If I were you, I'd trace back to David Knowles, born about 1798 in Sampson Co., NC, son of John Knowles, Revolutionary War veteran.From there, I'd follow his family into Georgia and Florida.It might not be your line but it just seems to me that it may be.