Thank to the information provided by Sonja Hoffman, I have come to the conclusion that James Sidney Alexander is the son of David Alexander and Mary McClatchey, for reasons detailed below.
There were three men named James Sidney Alexander born in North Carolina in the early 1800s.
James Sidney Alexander, b. 1828, son of Jane A. LEWIS and (James) Leander ALEXANDER, died 1853.
James Sidney ALEXANDER, b. 1811, son of Benjamin and Mary Alexander, married Mary Allen and Anna Allison, died DeWitt, TX, 1888.
James Sidney 'Sr' ALEXANDER, b. 21 May 1816, NC, son of Mary MCCLATCHEY and David ALEXANDER, d. 24 December 1899 in Hunt Co, TX. He married twice, to Mary FENLAW and Margaret Elizabeth MCDANIEL.
All three men died in separate places, and sufficient information is known about them to conclude that they are three individuals. Ergo, the James Sidney Alexander we find in Hunt Co, TX, is not the son of (James) Leander Alexander nor Benjamin Alexander. Both of these men, are, however, offshoots of the Mecklenburg Alexanders. David Alexander (blacksmith), was very likely a Mecklenburg Alexander as well, and so the use of the name 'James Sidney' for three men in this time and place suggests they were named after a common ancestor.
Mary McClatchey and David Alexander (blacksmith) had eleven children, one of whom was a son named Sidney. His birth date is not known, but it would have been after 1802, and most likely before 1818, given the oldest and youngest dates known for their children. Birth dates for most of their children are unknown. James Sidney Alexander b. 1816 is thus the right age to be one of their children.
James Sidney Alexander was a Methodist, possibly a lay minister, and a blacksmith. Mary McClatchey and David Alexander were Methodists, and their son Hamilton Lorenzo Dowell Alexander was one of the founders of the Hennegar Chapel Methodist church in Bradley Co, TN. David Alexander was a blacksmith also. Blacksmithing was a family business; members of iron families kept the secrets in the family and married into other iron families. This was part of early attempts to monopolize American iron production through nepotism. Early McClatcheys and their in-laws were blacksmiths, miners, owned forges and furnaces, participated in mining companies, etc.
James Sidney 'Sr' ALEXANDER had a son named David Lorenzo Alexander -- this would be his father and older brother's names. He migrated to Hunt Co, TX, home to Allen Black MCCLATCHY and Samuel Hamilton McClatchey, two sons of Adolphus Patton McClatchey. Descendants/relatives of Allen McClatchey, son of Hamilton McClatchy Jr would also migrate here. In fact, his daughter Mary Elizabeth Alexander married Allen Black McClatchy. They would have been second cousins; early McClatcheys married relatives quite frequently.
Can anyone offer information to substantiate or refute this theory?