1. Trigg County Marriages, 1820-1900 (online at the Trigg County KYGenWeb site):

Thompson

Moses

Smith

Claracy

29 Mar 1831

2.  1830 Census Index (online at GenealogyLibrary.com):

1830

Thompson, Moses

KY

Trigg Co.

Cadiz

p. 11

3.  1840 Census Index/Images (online at Ancestry.com; Image #6-7 of 67; extracted by Diana Gale Matthiesen):

1840

KY

Trigg Co.

pp. 279B-280A

Ln. 11

Moses Thompson

021 101 - 200 010

000010-000000

100000-102000

0103000

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
2 white males	5-9	1830-1835	= James (b. 1834/5) = Jonathan
1 white male	10-14	1825-1830	= ?
1 white male	15-19	1820-1825	= ?
1 white male	30-39	1800-1810	= Matthew (b. 1807)
2 white females	4 or under	1835-1840	= Mary (b. 1838) = Louisa (b. 1836/7)
1 white female	20-29	1810-1820	= Clarissa (b. 1813)
1 male free colored	55-99	1740-1785	= ?
1 male slave	9 or under	1830-1840	= ?
1 female slave	9 or under	1830-1840	= ?
2 female slaves	24-35	1804-1816	= ?
1	persons employed in agriculture
3	persons employed in manufacture and trades

4.  1850 Census Index/Microfilm (online at GenealogyLibrary.com): Dist. 1, Trigg Co., KY, Roll 219, p. 359, 464/464, enumerated 7 Sep 1850 (extracted by Diana Gale Matthiesen):

Moses S. Thompson	47	M	Farmer	3200	Kentucky
Clarisa H. Thompson	36	F			Virginia
James P. Thompson	15	M	Student		Kentucky
Louisa C. Thompson	13	F			Kentucky
Mary Thompson	11	F			Kentucky
Robert Thompson	9	M			Kentucky
Wm. F. Thompson	7	M			Kentucky
Harriet B. Thompson	3	F			Kentucky
Moses Thompson	1	M			Kentucky
Joseph Helbling	36	M			Switzerland

Head-of-household is indexed as "Mary S. Thompson" at GenealogyLibrary.com and as "Mac S Thompson" at the Trigg Co. KYGenWeb site.  It is Moses, but you can only see it as Moses if you know that is what it should be.

5.  Trigg County, Kentucky, Cemeteries:  East End Cemetery [link died] (online at Trigg County KYGenWeb site):

Thompson Moses, April 4, 1807--March 16, 1884

Thompson Clarissa H., wife of Moses, born Culpepper Co., Virginia April 17, 1813--Dec. 29, 1886 (Smith)

Obviously not a straight reading of the stones, and they acknowledge that information has been added (by the compilers and/or editors).

6.  Barney Thompson. MS. The Thompson Family of Prince Edward County, Virginia, Butler and Trigg Counties, Kentucky, and the Florida Parishes of Louisiana:  the Descendants of Thomas Thompson, 1749-1810.  Copies at Western Kentucky University, the Filson Club Library, and the Indiana State Library, Indianapolis.  (Excerpts courtesy of the author.) 

7.  Barney Thompson, ed.  1996.  "Letter to the Editor of the Kentucky Telephone, December 20, 1889."  Pages 6-10 in Pioneers of Trigg County, Kentucky, As Seen through the Biographical and Genealogical Articles of Cyrus Thompson in the Kentucky Telephone and the Cadiz Record, 1889-1899.  [MS] (online at the Trigg County KY GenWeb site). 

8.  William Henry Perrin, ed.  1884.  History of Trigg County:  Historical and Biographical.  F.A. Battey Publ. Co., Chicago (boldface added):

p. 204

MOSES S. THOMPSON was born April 5, 1849, in Trigg County; he is the youngest child of a family of seven born to Moses and Clarissa H. (Smith) Thompson, who were both natives of Virginia.  His mother was born in 1813, and when a child came to Trigg County with her parents, all coming here on horseback.  They settled on a farm about three miles from Cadiz, where she has since lived.  His father was born in 1807; he died March 16, 1884.  When a boy he was apprenticed to the tanner's trade, and this business he followed through life; also engaged in agricultural pursuits.  He owned previous to the war from thirty to forty slaves...

9.  Email from Robert D. Steele.

10.  Messages in the Wharton Family Genealogy Forum (online at GenForum.com).

11.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).