Census 1920: Benjamin Coffey / b: abt 1846 in KY / Head / Living in Washington, Wayne, Iowa
Census 1910: B C Coffey / b: abt 1846 in KY / Head / Living in Washington, Wayne, Iowa
Census 1900: Benjiman C Coffey / b: abt Nov 1845 in IL / Head / Living in Benton, Wayne, Iowa
Census 1880: Benjamin C. Coffey / b: abt 1846 in KY / Head / Living in Jackson, Sullivan, Indiana
Census 1870: Benj Coffer / b: abt 1846 in KY / / Living in Christian, Illinois
Census 1860: Benjamin Coffee / b: abt 1846 in KY / / Living in Subdivision 66, Shelby, Illinois
Census 1850: Benj Coffer / b: abt 1845 in KY / / Living in Sangamon, Illinois

Ancestry.com 1880 census:
Benjamin C. COFFEY
 Age:   34
 Estimated birth year:   <1846>
 Birthplace:   Kentucky
 Relation:   Self
 Home in 1880:   Jackson, Sullivan, Indiana
 Occupation:   Coal Operator
 Marital status:   Married
 Race:   White
 Gender:   Male
 Head of household:   Benjamin C. COFFEY
 Father's birthplace:   KY
 Mother's birthplace:   KY

Note that this census says Ben was born in Kentucky -- and same census says brother William was born in Illinois. This suggests family data on birth place of Ben may be wrong. Also obituary of father Newton Eli says he moved to Illinois in 1846, after Ben was born.

Believe that Benjamin served in the Union Army during the Civil War - - sort of. Found a record that Benjamin C. Coffey enlisted as a Private in Company “U” of the 3rd Illinois Calvary Regiment on 2 March, 1865. He would have been age 19. However Lee surrendered in April of 1865, and Ben was mustered out on 21 May 1865. He served less than 3 months, and probably never finished his training?