Sanford Isaiah Denham (June 1822 - April 08, 1882)
Isaac G Denham (1843-6 -- Aug. 27, 1897)
John Wesley Denham (Aug. 11, 1868 - May 8, 1945)

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No "Denham" in 1818-1850 Census for Franklin County, IL
the bracket () are my comments

1860 Federal Census, Northern Township, Franklin County, Illinois
ftp://ftp.rootsweb.com/pub/usgenweb/il/franklin/


a433 Sanford Denham 37m KY 600/325 Farmer  (?dob 1823)
Reeaines        35 f KY Housekeeper
John           17m KY Domestic Farmer
Isaac G        14m KY                      (?dob 1846)
Allen               12m KY                 (?dob 1848)
Sirene A        10 f KY
Jasper                8m IL
Mary Jane         7 f IL                     (daughter, dob 1854)
George W         4m IL
Charlotte         2 f IL
Lewis Gulley        76m VA Domestic Father

                                              (? left Kentucky around 1850 - 1851)

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1870 Federal Census, Northern Township, Franklin County, Illinois

165/165 Denham, Allen 21m IL 300/200 Farmer     (?dob 1849)
Lorinda              17 f IL KH


167/167 Denham, Sanford 48m KY 800/400 Farmer   (?dob 1823)
Rachel               47 f KY KH                 (wife)
Isaac               18m IL                      (?dob 1852)
Clementine             7 f IL
Ransada           2 f IL

168/168 Denham, Isaac 25m IL 400/200 Farmer     (?dob 1845)
Caroline        21 f IL KH                      (?dob 1849)
John W           2m IL

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1880 Federal Census, Northern Township, Franklin County, Illinois

367/384 Denham, Isaac   37m KY KY KY Farmer     (?dob 1843)
Caroline  w     32 f IL IL IL kh                (?dob 1848)
John W         s    12m IL
Elvalus        s    10m IL
Daniel R  s         5/12m IL Feb

370/387 Denham, Allen   32m KY KY KY Farmer     (?dob 1848)
Nancy J        w     27 f IL KY IL kh
Willis H       s     4 m IL
Alice          d       2 f IL
Minnie         d       1 f IL

387/404 Denham, Sanford 59m KY VA VA Farmer     (?dob 1821)
Rachel R  w     57 f KY NC KY kh
Cansadia  d     14 f IL
Belt, Sarah R  Gd      8 f IL KY IL blind
Belt, Havana   Gd      5 f IL KY IL

---------------------------------
Sanford Isaiah Denham --> pastor of the Pioneer Baptist Church of Franklin County Ill.

From a web posting to a genealogical site:
The info I have on Nancy Jane is: She was born in 1854
Married a George W. Bain (my GG grandfather), 
One of the children was Hester Florence Bain 
(my great grandmother), Nancy Jane's father 
and mother were Sanford Denham and Rachel Gulley, 
and he was the pastor of the Pioneer Baptist Church 
of Franklin County Ill.