Thomas Garnett was mentioned in the 15 March 1838 will of his father-in-law, Barbee Spindle, proved 16 April 1838. Unto daughter Virginia Garnett the tract of land now in possession of her husband Thomas Garnett called the Dingen tract, and negroes Bob, Annetend[? microfilm copy not clear], Letty, Achilles, Robert, Lindsay, Lucy, Eliza, Anthony, Caroline, Martha, Mary & Chaney … My son-in-law Thomas Garnett to account for $1,900, and the said Philip & Marcella to receive $775 less than the seventh bequeathed them. [Essex County, Virginia, Will Book 24, pages 271–272.]

On 16 April 1838, Daniel Rennolds, Thomas B. Garnett, William Oliver, Muscoe Garnett Jr., Lewis Rennolds, Richard Motley, George T. F. Lanier, and Philip J. Rennolds were bound in the penalty of $65,000 for Daniel Rennolds’s and Thomas B. Garnett’s executorship of the estate of Barbee Spindle, deceased. [Essex County, Virginia, Will Book 24, page 272–273.]

On 12 December 1838, sales of the estate of Barbee Spindle were made. Includes Robert and Ned to Muscoe G. Wood; Ryburn to Reuben Saunders; John to Thomas B. Garnett; Humphrey to Mrs. Fanny Spindle; Polly, Nancy, Nicy, and Jim to William Gray; Betty to John S. Parker; Winny to Muscoe Garnett; Jerry to George T. F. Larimer; Irene to John A. Miller; Tom to Samuel Anderson; George to John G. Tod; and Charity & Phil to James Lee. [Essex County, Virginia, Will Book 24, pages 385–387.]

The estate of Silas B. Spindle, deceased, in account with Daniel Rennolds and Thomas B. Garnett, executors, from 1838 to 1839 was ordered recorded 15 July 1839. [Essex County, Virginia, Will Book 24, pages 392–397.]

On 9 July 1839, an inventory and appraisal of the estate of Frances Street was made by Larkin Hundley, Thos B Garnett, and Lewis B Montague. [Essex County, Virginia, Will Book 24, page 411.]

On 17 February 1840, Robert B. Micou, William Blackburn and Thomas B. Garnett were bound in the penalty of $1,000 for Robert B. Micou’s administration with the will annexed of the estate of James E. Clarke, deceased. [Essex County, Virginia, Will Book 24, page 446.]

1850 U.S. Census, Essex County, Virginia
Page 69
Dwelling 61, Household 61
Garnett, Thomas B., 58, male, farmer, value of real estate $12,000, born in Virginia
Garnett, Virginia, 34, female, born in Virginia
Garnett, Thomas, 10, male, born in Virginia, in school
Garnett, Jenifer, 8, male [sic], born in Virginia, in school
Garnett, Leslie, 6, male, born in Virginia, in school
Garnett, Griffin, 4, male, born in Virginia
Spindle, Virginia, 21, female, born in Virginia
Mitchell, Hezekiah, 24, male, teacher, born in Virginia

On 21 May 1857, Thos B Garnett witnessed the will of John P. Dunn. [Essex County, Virginia, Will Book 28, pages 25-26.]