It's always best to find out how people in any place and time view themselves -- what they see as their strengths, what they see as their weaknesses, and what they consider too obvious to ever need to be mentioned explicitly. That's true even when, as is the case in Thomas's book, the account is so infected with wishful thinking that it might remind us of a cartoon; we at least get to see how Thomas and people like him wished to think of themselves. Bear in mind also that we also have cartoonish perceptions both of ourselves, and of those separated from us by time or distance.
Regardless, the Edward J. Thomas who was my great-great-great grandfather was born in 1806, whereas the author was born in 1840, so they are clearly not the same person. What's more, the author's family owned several large plantations, whereas my relatives lived in a small household.
That household included a son Edward who was born in 1839, which is close enough for a possible match, given the records of that time. However, records indicate that on 20 September 1862 he was deployed with the 5th Florida Infantry but had to be "left sick at a private house" near Richmond. On 8 December 1862 he died in a Richmond hospital. He did not survive to write a nostalgic retrospective of the antebellum South.
UPDATE 5/30/2018 -- Ancestry.com shows this about "Edward J. Thomas" living in Quincy, Florida: "Enlisted in Company C, Florida 6th Infantry Regiment on 11 Jan 1862. Promoted to Full 5th Sergeant on 01 Oct 1863. Promoted to Full 2nd Lieutenant on 01 Oct 1864." This appears to be my great-great-great grandfather unless his son also had the middle initial "J", in which case it may have been the father who died of illness and the son who was promoted to an officer. However, the son seems not to have had children, which suggests (but does not prove) he did not survive the war. The source given is Soldiers of Florida in the Civil War: Biographical Rosters of Florida's Soldiers 1861-1865.
A similar fate befell Samuel J. Bradshaw. He had been born in 1820 in South Carolina, and during the Second Seminole War he had come to Florida as part of Snodgrass' North Alabama Mounted Volunteers. At the start of the War Between the States, he was still in Florida, and ended up enlisting as a private in Company B of the 8th Florida Infantry, although he was by then in middle age. Whether his age contributed to his ultimate fate is not clear, nor is the particular ailment that felled him, but on 19 February 1863 he died, being subsequently buried in the University of Virginia Confederate Cemetery. The records say he died, not that he was killed, so he also seems to have been a casualty of disease. This was by no means uncommon; in most wars, disease has killed more men than combat.
Samuel J. Bradshaw left behind, among others, an 11 year old son named William Henry Bradshaw. This son grew up to marry Louisa Thomas, the daughter of Edward J. Thomas and the sister of Edward Thomas; William and Louisa became my great-great grandparents.