John Oxford was the son of Sarah Oxford. He was born around 1814 in Tennessee. He is mentioned in the 1840 census living with his mother.
On September 2, 1836 he married Isabel Beggs in Union County, Illinois. She was born around 1816 in Illinois.
I can not find them in Illinois after this time.
I did find a John and Isabel Oxford living in Liberty, Stoddard County, Missouri in the 1850 Census. From that document they have 2 children.
James Oxford 1845
John Oxford 1848 (Davis Co, Missouri)
I believe some of the Oxford and Lewis families did move to Missouri. And then some moved back to Illinois.
Questions/ More Research
1. Research more and find documents for this family.