If Sanesac or Senesac is a Canadian or French Canadian name, it could be the father was Jean - changed to John.

You can search in Canada at ancestry.com or familysearch.org

But, following up on the Civil War Soldier, I googled his complete name in Parenthesis, "John B. Senasac" and found this teaser at ancestry.com (which I don't subscribe to)

Sarah L. Gray, Born in Arkansas, USA on 15 May 1848 to Thomas Shannon Gray and Julia Elizabeth Bales. Sarah L married Pierce Whitley Crisp and had 13 children. Sarah L married John B Senasac. She passed away on 25 Oct 1917 in Texas, USA.

if it's the same family, Frances Breaders died, John remarried, and lived in Texas. And the age of Sadie when she married in Texas is young, so maybe she was there with her father too.

Here is Sarah L. Gray's first spouse, then a list of the kids, then John B. Senasac as her 2nd spouse.

Spouse(s)
Pierce Whitley Crisp
1820-1896

Children
Baby Unknown
Octavie Crisp
Mary Ellen Crisp
Minnie Jane Crisp
Thomas Gray Crisp
Alice L Crisp
Tony Antony Crisp
Tony Artney Crisp
Artemissa Crisp
Julie Crisp
Ephrium Carter Crisp
Martha Dee Crisp
Johnnie Crisp

spouse:
John B Senasac

I see that Sara L. Gray Crisp, under that name, is buried also in Nacodoches county, Texas. Don't know what happened with the marriage to Senasac.
http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=10...

The person who posted this grave:
http://www.findagrave.com/cgi-bin/fg.cgi?page=mr&MRid=46...

You could contact him.