1850 census of Patrick Co., Virginia, Northern district, enumerated 20 Aug, lists as family #67/69:
Gabriel Dehart, 39, farmer; Martha, 31; Sarah, 16; Stephen, 15; William, 12; Henry, 10; Lucinda, 7; Green, 3; Jno., 1/12. All born in Virginia.

1860 census of Patrick Co., Virginia, North division, Rock Castle P.O., enumerated 29 June, lists on p. 19 as family #126/129:
Gabriel Dehart, 49, farmer; Martha, 40; Sarah, 25; Steven, 24; William, 22; Henry, 20; Lucinda, 18; Green, 13; John, 10; Martha, 4; Nathaniel, 2; Thomas N., 2; Gabriel Dehart Sr., 79; Charity, 73. All born in Virginia.

1870 census of Patrick Co., Virginia, Smiths River township, enumerated 16 Sep, lists on p. 53 as family #393/416:
Dehart, Stephen H., 35, farmer; Martha, 52; Green, 21; John, 20; Martha, 15; Nathaniel C., 13; Thomas N., 12. All born in Virginia.

Note that Nathaniel and Thomas, who were listed as the same age in 1860, no longer are. It is possible that they are not brothers. In the 1880 census, Thomas is listed as a grandson of Martha, but Nathaniel is not listed in the census, so his relationship cannot be compared.

1880 census of Patrick Co., Virginia, Smiths River district, enumerated 28 June, lists on p. 31 as family #277:
Dehart, Martha, 62, widowed, keeping house; Weaver, Jesse M., 29, son-in-law, farmer; Martha E., 26, dau; Ida D., 3, granddau; Louiza E., 1, granddau; Nanie M., 3/12, b. Feb, granddau; Dehart, Thomas N., 22, grandson, boarder; Weaver, Isaac M., 22, hireling, works on farm. All born Va Va Va.