"The Archives of the Pioneers of Tazewell Co., Virginia", 1992, by Netti Schriener-Yantis, footnote #85 on page 263, contains a quote from G. T. Swain's 1927 "History of Logan Co., W. Va", p. 78, “Thomas K. had three sons, one of whom (Charles) was a soldier in the Mexican War.”

I have not found Charles in the census. He was not living in Logan Co., Va. Since the U.S.-Mexican War was from 1846 to 1848, Charles was probably born before 1830. Since the Swain article does not say that Charles died in the war, most likely he survived, but established his household outside of Logan County. Since Clark is such a common surname, and I do not know his year of birth, there would be no way of telling which of the Virginia-born Charles Clark(e) listings in the 1850 census would be him.

Possibilities include a Charles Clarke age 23, boatsman, living with the family of St. Clair Rains in Kanawha Co., Va (there is another unrelated boatsman in the household; St. Clair seems to be their employer); Charles Clarke age 22, blacksmith, living in a 50-resident hotel in Louisa Co., Va; and Charles Clark, age 24, labor, with wife Nancy age 22 and daughter Lucy age 1 in Elyria, Lorain Co., Ohio.