I was browsing your message history.You said you thought you might have found the parents of William, did you check land and probate records for his "possible" father?See if your William shows up as an heir.
1880 census Fannin Co, TX:
Category: Name;Relationship to head of household; Marital Status; Gender; Race; Age; Birthplace; Occupation; Father's Birthplace; Mother's Birthplace.
Mary MANLEYWifeMFemaleW43TXKeeping HousePACAN
William MANLEYSonSMaleW20TXFarm LaborerNYTX
John R. MANLEYSonSMaleW2TXNYTX
1870 census Fannin Co, TX:
Manly(sic), Daniel, 51, b NY - farmer
" Mary A., 31, b TX
" Mary, 12, b TX
" William T., 9, b TX
1860 census Bowie Co, TX:
Manly(sic), D., 43, b NY - Blk Smith
" Mary B., 2?, b TX
" Mary J., 2, b TX
" Wm T., 4/12, b TX
I would say the following census would tie these brothers and mother to the above records.
1910 census Delta Co, TX:
Manley, John L., h, 31, sgl, b TX, OH, TX
" Mary, mth, 73, wid, b TX, OH, TX
Manley, William T., h, 50, M(1) 25 yrs, b TX, OH, TX
" Rosea(sic), w, 40 M(1) 25 yrs, ch ??, 6 lvg, b MO, MO, IA
" Emma, d, 23, sgl b TX
" Emos, s, 21, sgl, b TX (believe this is son Amos)
" Fannie, d, 17, b TX
" Willie, d, 13, b TX
" Chas, s, 9, b TX
" Truman, s, (4?), b TX (age not real clear, looks like 4)
[You mention in other posts that William died about 1906/07, but he is still alive in 1910.Youngest son is your Truman]
If the above John and Mary are brother and mother of William, then this looks like the same ones.
1900 census Hunt Co, TX:
Manley, Mary Manda, h, b Dec 1830, 61 wid, 5 ch, 2 lvg, b TX, PA, TX
" Jno Richard, s, b Oct 1878, 21, sgl, b TX, PA, TX
I would look for marriage record for Daniel and Mary in Bowie Co, TX.
Happy Hunting (^_^)