Checked Five Volumes of Cemetery Records Nothing listed for William and/or Martha White.
4 Volumes of Obituaries, Obsequies and Notices of Death From The Sullivan Democrat Compiled by: Ann and Art Miller which covers the years as follows:
1870-1879 1880-1889 1890-1899 1900-1905
1890-1899, Pg. 9 Tuesday, 25 Mar 1890 Farmersburg
The saddest news this week is the death of four of our citizens, Zimri Bennett; Charley Wood; Wm. White; and John Pittman.Who can say this is your William White.
Checked Indiana Wills Phase 2 1850-1880 By Charles M. Franklin 1987 Nothing listed for William White in Sullivan County, Indiana.
Checked Death Records 1882-1920 Vanderburgh county, Indiana in case William or Martha ended up in the state hospital, again found nothing.
I looked at the census records 1860-1880 for William and Martha to get an idea for whom I was searching.Noticed they had 3 children listed on 1860 census the only child I was able to identify in Sulivan county records was Verilla who first married John Wilkins and had 2 daughters and second marriage to Joseph C. Blair. I'm sure you already have her data, if not, let me know I will send it.By 1900 census Verilla was living in Clay county, Indiana with one of her daughters.
I'm wondering if William and Martha might have moved out of county with one of the sons, as it's like they fell off the face of the earth after 1880 census.
Have you found William and Martha on 1850 census? Do you know what happened to the their sons?