1840 U.S. Census, Essex County, Virginia:
Dunn, Samuel C.
1 male age under 5 [this would be Richard]
1 male age 15-20 [this would be Samuel, age low]
2 females age under 5 [this would be Sarah and possibly Mary]
2 females age 5-10 [one of these would be Francis and maybe Mary or Virginia]
1 female age 20-30 [this would be Sarah]

1850 U.S. Census, Essex County, Virginia
Page 96
Household 545, Family 545
Dunn, Samuel, 40, male, laborer, $188 real estate, born in Virginia
Dunn, Elizabeth, 39, female, born in Virginia
Dunn, Sarah, 18, female, born in Virginia
Dunn, Mary, 15, female, born in Virginia
Dunn, Richard, 14, male, born in Virginia
Dunn, Frances, 11, female, born in Virginia
Dunn, Virginia, 10 female, in school, born in Virginia

Thomas H. Dunn married Mary Elizabeth Dunn on 7 January 1857 in Essex County, Virginia. Both were 23, both born and living in Essex County, Virginia. He was a farmer. His parents were Edmund and Lucy Dunn; hers were Sam and Elizabeth Dunn. Peter Ainslie performed the ceremony. [Essex County, Virginia, Marriage Register 1, page 4, entry 19.]

1860 U.S. Census, Essex County, Virginia:
Dwelling 600, Family 584
Dunn, Thomas, 26, laborer, $50 personal estate, unable to read or write
Dunn, Mary E., 25
Dunn, Columbia A., 7/12

1870 U.S. Census, Essex County, Virginia:
Dwelling 1631, Family 1631
Dunn, Thomas, 36, farmer, $125 personal estate
Dunn, Mary, 36, keeping house
Dunn, Columbia A., 9, at home
they were double-listed in Dwelling 1821, Family 1821:
Dunn, Thomas, 36, work in grist mill
Dunn, Mary, 32, keeping house
Dunn, Columbia, 9, at home

1880 U.S. Census, Middlesex County, Virginia
Jamaica District, page 261
Dwelling 19, Household 19
Dunn, Thos. H., white, male, 46, miller, born in Virginia, both parents born in Virginia
Dunn, Mary, white, female, 46, keeping house, born in Virginia, both parents born in Virginia
Dunn, Columbia, white, female, 20, teacher, born in Virginia, both parents born in Virginia
Griffith, Mary F., white, female, 13, servant, cook, cannot read or write, born in Virginia, both parents born in Virginia

On 7 July 1883, an agreement was drawn up by the heirs of Edmund Dunn, deceased. His children were Thomas H. Dunn (who married Mary E. Dunn), Indiana Dunn (who married John Hay), and Lucy Dunn (who married John J. Dunn). [Essex County, Virginia, Deed Book 54, pages 205–206.]