Updated info:
Jennie Foster was William Wallace 2nd wife.
Francis G. was his son by his first wife, Rebecca. He was born Oct 3, 1879. Found this on the 1880 Census
1880 United States Federal Census > Texas > Milam > Precinct 5 > District 105 image 7
Ercanbrack William W 23 farmer MS NY NY
Rebecca 21 wife TX TX OH (died by 1885)
Francis G. 8/12 Oct [1879] son TX MS TX
After Jennie died April 7, 1927, William must have moved back to Milam County, as the Texas Death Certificates give this:
William Wallace Ercanbrack
Born: Dec 18, 1856 Mississippi
Died: 14 Feb 1936 79 yrs 2 months 4 days widowed
Wife: Jennie Foster
Burial: Val Verda Cemetery, Holland (Milam Co) TX