Thomas Washington Cox was born in Tennessee, and labored as a Baptist minister in Alabama and Texas (and perhaps Tennessee), before defecting to the Campbellites.
He was the son of Greenberry Cox and Temperance Cross, and born circa 1803.[i] He married Melinda D. Bradford August 22, 1823 in Rutherford County, Tennessee. They had at least 9 children (her obituary suggests 9 children survive her). After the death of Melinda, he married Mrs. Mary Linzey in Fayette County in September 1848. However, she does not appear with him on the 1850 census.
In 1833, Thomas W. Cox served on a committee of 5 appointed by the Alabama Baptist State Convention to establish a seminary (“Baptist Literary Institution”) on the “Manual Labor Plan.” He served on the Board of Directors at least until 1835. Cox preached at Ebenezer/ Tuscaloosa City (Holcombe, p. 149), Hebron in Jefferson County (p. 232), Good Hope in Talladega (p. 254), and perhaps Elyton in Jefferson County (p. 234; if the “W” was incorrectly inverted to an “M”). In 1835 he was on the “Committee of Vigilance” of Tuscaloosa, a group opposing vices such as gambling.

“Elder Thomas W. Cox lived here some time; and went from here to the province of Texas. Mr. Cox was an intelligent man, and might have been useful in the cause of the Master; but he engaged in the mercantile business, as too many preachers have done, and failed—then studied law, and it is probable, is practicing in Texas. He was, like many other ministers, rather arminian in his doctrinal views; but was highly respected as a minister of the gospel, until those misfortunes came his way; or rather, until he put himself in the way of them. Mr. Cox, has preached a great deal in Alabama.” Holcombe, p. 254
An Early History of Fayette County Texas by Leonie Rummel Weyand & Houston Wade (LaGrange, TX: LaGrange Journal Plant, 1936, pp. 49-52, 140, 172, 220, 224, 285, 297) has an interesting account of Cox, but gets some things wrong about him. (Such as saying he was born in Alabama in 1785, and that he came to Texas in 1822 with Austin’s 3rd Colony. He was not born in Alabama, was not that old, and if he came to Texas in 1822, he did not stay.)
Cox owned (apparently due to his military service) 640 acres in Fayette County, 13 miles east of La Grange.
It is not certain, but perhaps Cox was no longer active in the ministry after his exclusion from the church at LaGrange in 1841. He practiced law in Texas. He died February 6, 1852, of congestion of the brain, and is buried in an unknown grave – mostly likely the Rutersville Cemetery, but possibly in La Grange.[ii]
T. W. Cox served on the “Texas Monumental Committee,” the group that published the newspaper The Texas Monument (published at LaGrange, Texas), as well as collected funds to build a monument to the Mier Expedition prisoners.
In the La Grange Journal newspaper, 1937, 1938:
T. W. Cox is mentioned in Flowers and Fruits from the Wilderness by Z. N. Morrell, a history of early Texas Baptists. Morrell and Cox were Baptist ministers, and contemporaries in the Union Baptist Association. Morrell advised the church of which Cox was a member and pastor about his Campbellite doctrine and recommended that they take action against him.
[i] There are some discrepancies on his birth year, but 1803 seems to come closest to all the best-attested facts. The Thomas Cox in 1830 in the Davidson County, Tennessee census is probably him.[ii] His wife Melinda was buried at Rutersville, and this is probably in general where or close to the area where they owned the 640 acres.