1880 census Bayou San Miguel, Sabine Parish, LA:
Category: Name;Relationship to head of household; Marital Status; Gender; Race; Age; Birthplace; Occupation; Father's Birthplace; Mother's Birthplace.
George M. PERSONSSelfMMaleW27TXFarmerTNAL
Mary J. PERSONSWifeMFemaleW22LAKeeping HouseSCGA
Sarah L. PERSONSDauSFemaleW3LATXLA
Alonzo L. PERSONSSonSMaleW1LATXLA
Could this be your George?
1870 census DeSoto Parish, LA
Persons, George, 20, b TX - farm laborer - living in the household of W. W. Woods, b MS and his family who were b LA.
You didn't mention Martha/Mary remarried, you will need to look for her death certificate under that name.Are you sure her maiden name was White?Her daughter marries a White.
1910 census Natchitoches Parish, LA:
Persons, Alonso(sic), h, 29, M(1) 5 yrs, b LA, LA, LA
" Emer(sic), w, 20, M(1) 5 yrs, 2 ch, 2 lvg, b LA, AL, LA
" John R., s, 3, b LA
" Mary C., d, ?/12, b LA
White, John J., h, 33, M(1) 11 yrs, b LA, LA, LA
" Sara(sic), w, 25, M(1) 11 yrs, 2 ch, 2 lvg, b LA, LA, LA
" A____, d, 9, b LA
" Maggie, d, 7, b LA
Bruster, Dan, fth-in-law, 64, M(1) 16 yrs, b LA, LA, LA
" Martha, mth-in-law, 77, M(2), 16 yrs, 6 ch, 2 lvg, b LA, LA, LA
1900 Natchitoches Parish, LA:
Bruster, Dan, h, b Jun 1844, 55, M 17 yrs, b LA, KY, KY
" Martha, w, b Jun 1830, 69, M 17 yrs, 5 ch, 3 lvg, b AL, AL, AL
White, John, h b May 1876, 24, M 2 yrs, b LA, LA, LA
" Sarah, w, b Apr 1883, 17, M 2 yrs, 0 ch, b LA, LA, LA
Note years married for Dan and Martha do not match up from one census to the other, but if they were indeed married for 17 yrs as shown on 1900 census, I would say her first husband George died after 1880 census and prior to about 1883.
Marthaville is in Natchitoches Parish, LA.Here is a handy dandy site to locate county for towns/cities in the U.S.
I do not have access to online census index for 1930 in LA.Your local Family History Center has a subscription to Ancestry.com and you can use their computer to search Ancestry, which has an every name index for the 1930 census.
Happy Hunting (^_^)