You didn't include any dates, or approximate dates, nor locations in your query.I looked at your message history and the one you posted on the Stroope family forum had much more information.But, I thought you meant some stayed in AR and some moved to TX.
1880 census Lampasas Co, TX:
Category: Name;Relationship to head of household; Marital Status; Gender; Race; Age; Birthplace; Occupation; Father's Birthplace; Mother's Birthplace.
J. P. STROOPESelfWMaleW38ARFarmerARAR
G. A. STROOPENieceSFemaleW18TXK. HouseARAR
1870 census Gonzales Co, TX:
Stroupe[sic], John B., 28, b AR - no land/personal 400
" Lebernia, 19, b MS
" William, 1/12, b TX, born May
Stroupe, Henry, 60, b LA, land 520/personal 225
" L____, 57, b VA [can't read her name]
Stroupe, James, 25, b AR - no land/personal 80
" Matilda, 19, b Germany
" Ally, 2, b TX
1860 census Gonzales Co, TX:
Swoup[sic], Henry, 50, b LA - land 210/personal 800
" L., 50, b VA [only initial "L"]
" S.C., 21, b AR
" John, 19, b AR
" Isaac, 16, b AR [maybe this is James on 1870 census]
Alsop[sic], E. S., 47, b TN
" Robt., 21, b TN
" Isaac, 18, b MS
" Wm., 16, b MS
" Centhia, 11, b MS
" Loe, 9, b MS [maybe Libernia, wife of your John]
" H____, 6, b MS (male) - can't read name
" Thos., 3, b TX
[You should find this family on the 1850 census in MS and mother should still be alive]
Be sure to check Gonzales Co, TX GenWeb site:
And the "archived" GenWeb site for the county, too.
I don't know why GenWeb counties have both, some basically have the same information, and other times they will have different records.
I typed in Stroope in the search feature and found marriage records for the following, be sure to try all the variations of the spelling of that surname:
Stroope, Henry - Lelony Langford, 10/26/1854
[maybe a second marriage for Henry?]
Stroop[sic], J.P. - Lois M. Alsup, 5/6/1868
" James - Matilda Frederick, 11/13/1866
" W.F. - Sallie Duren, 12/31/1896
If you're trying to find descendants of William, who was supposed to have the photo of John, I tracked him and wife Sarah/Sallie, daughters Loucie and Florence through 1900 & 1910 Gonzales Co, TX; 1920 Atascosa Co, TX and 1930 Hays Co, TX.In the family story handed down, instead of William moving "to" Gonzales Co, TX, I think he moved "away" from Gonzales Co.
You might post a query, see if someone can find marriages and children for Lucie/Loucie and Florence.Then you could look for their families and descendants, too.
Happy Hunting (^_^)