I can tell you've found the family on the 1880 census.You can add some children to Henry from the 1860 census Brazoria Co, TX:
Maner, H.C., 37, b SC " S., 36, b SC " Marcia, 12, b TX " Alice, 7, b Fla " Saml, 5, b TX " Lucy A., 4, b TX " Mary, 2, b TX Watson, Wm, 13, b GA
There are other Maners on that census, too.Do you know if they connect?
Jno.T, 28, b SC -- living alone.
Carrie, 17, b FL eumerated in someone else's household.
Next Door, also enumerated in someone else's household. J.W., 21, b GA
Have you checked land and probate records for Brazoria Co?It might give you an idea of when William died.When final sale of his land is made, all heirs will have to sign off to give clear title to the buyer, and you can pick up more of his children.