1.  Jordan R. Dodd, ed.  1993.  Illinois Marriages:  Early to 1850.  Liahona Research, Orem, UT (Broderbund CD-228):

Fisher, John T.

Dowden, Belinda

Oct 13, 1836

Greene Co.

2.  1840 Census Index/Images (online at Ancestry.com, Image #3 of 10; extracted by Diana Gale Matthiesen):¤

1840

IL

Greene Co.

Rawlings Pct.

Roll 60

pp. 92B-93A

Ln. 18

John Fisher

000 001 - 100 010

0100000

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	30-39	1800-1810	= John (b. 1817/8)
1 female	4 or under	1835-1840	= Mary (b. 1837/8)
1 female	20-29	1810-1820	= Belinda (b. 1815/6)
1	person employed in agriculture

John is in the wrong age category, but I don't think there's any doubt these are our subjects.  He is the only John FISHER in the county and is living four doors down from Henry DAWDEN.

3.  Census Microfilm Records:  Illinois, 1850 (Broderbund CD-301 — misindexed as "John F. Fisher"):  North of Apple Creek, Greene Co., IL, p. 122B, 214/214, enumerated 15 Nov 1850 (extracted by Diana Gale Matthiesen):

John T Fisher	32	M	Farmer		Ky
Belinda   "	34	F			Indiana
Mary G    "	12	F			Illinois
Isaac N   "	8	M			"
John Z    "	3	M			"
Esther Dowden	61	F			Virginia

Esther is Belinda's mother.

4.  WorldConnect (online at RootsWeb.com).