He was the only son of Thomas Mitchell Campbell, Sr. and Fannie Irene (Bruner) Campbell. He went by his middle name of Mitchell.
Married Erma Josephine Langston about 1915 in Palestine, TX.
Two sons: Thomas Mitchell, III and William Campbell.
Founded Campbell State Bank (Later renamed East Texas National). Palestine named Mitchell Base Ball Field after him. Was a Texas State Fire Insurance Commissioner when he died of a heart attack at the age of 40 years old.