With the given years Henry would be between 15-18 years old in 1870...
In NC I find one Henry age 35...
Also find one Benj. Roundtree as follows..but no Henry in Household

1870 NC, Craven County, Grantsboro PO, Page 491, sheet 2

ROUNDTREE, Benj., 53, Black, Farmer, born NC
Hannah, 58, Black, keeping house, NC
Alonzo, 12, farm labor, NC
Margaret, 06, NC
William, 04, NC
Issac, 04 months, NC

Assuming these younger children are grandchildren...at least the 6, 4 and 4 month old.

In Total there were 16 Roundtree (Black and Mulatto) in the index for this year in 5 different counties.

Vera