1a.  Christian Co., KY.  WHITE MARRIAGE BONDS IA, 1797-1817 (LDS Film No. 0465562, Item #1):

p. 169

Thompson, Jane to William Snadon

24 May 1815

There's no minister's return for Jane & William, but obviously the marriage did take place because, among other things, Jane is mentioned in her father's will as "Jane SNOWDEN" (see below). 

1b.  D.L. Murray & N.R., compilers.  1995.  Marriage Index: IL, IN, KY, OH, TN, 1720-1926 (Broderbund CD-2):

Snoden, Wm

Thompson, Jane

24 May 1815

Christian Co., KY

2.  1820 Census Index/Images (online at Ancestry.com):  not found, but there are many people known to be living in this part of Todd County in 1820 who are also missing.

3.  1830 Census Index/Images (online at Ancestry.com; Image #25-26 of 68; extracted by Diana Gale Matthiesen):

1830

KY

Todd Co.

Roll M19_41

p. 370

Ln. 26

William Snaden

211 001 - 001 000 100

200000-010000

These data indicate:

No., Race, Gender	Age Class	Therefore Born	Individuals Inferred
2 white males	4 or under	1825-1830	= William Jr. (b. 1828/9) = Son A
1 white male	5-9	1820-1825	= Alexander (b. 1824/5)
1 white male	10-14	1815-1820	= James (b. 1819/20)
1 white male	30-39	1790-1800	= William (b. 1794/5)
1 white female	10-14	1815-1820	= Daughter A
0 white female	30-39	1790-1800	=
1 white female	40-49	1780-1790	= Jane (b. 1796/7)
2 male slaves	9 or under	1820-1830	= ? ?
1 female slave	10-23	1806-1820	= ?

Jane is in the wrong age class, but surely these are our subjects.  Listed next to Nathaniel BURRUS, who is listed three lines from Thomas HADEN.

4.  1840 Census Index/Images (online at Ancestry.com, Image #7-8 of 18 — indexed "Snayaem"; extracted by Diana Gale Matthiesen):

1840

MO

Barry [now Dade] Co.

Smith Twp.

Roll M704_220

pp. 29A-29B

Ln. 11

William Snayden

001 110 100 - 000 100 100

8

0500000

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	10-14	1825-1830	= William Jr. (b. 1828/9)
1 male	15-19	1820-1825	= Alexander (b. 1824/5)
1 male	20-29	1810-1820	= James (b. 1819/20)
1 male	40-49	1790-1800	= William (b. 1794/5)
1 female	15-19	1820-1825	= Daughter A
1 female	40-49	1790-1800	= Jane (b. 1796/7)
5?	persons employed in agriculture

William's numbers do not add up, but I've definitely got the right page as (most of) the others around him do.

5.  1850 Census Every-Name-Index/Images (online at Ancestry.com; Image #78 of 95):  District No. 25, Dade Co., MO, Roll M432_398, p. 299B, 535/546, enumerated 18 Oct 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):

William Snoden	55	M		Farmer	8000	Virginia
Jane	53	F				Virginia
James	28	M		Farmer	800	Kentucky
Alexander	25	M		Farmer		Kentucky
William	21	M		Farmer		Kentucky

6.  1860 Census Index/Images (online at Ancestry.com, Image #16 of 24):  Kings Point P.O., Smith Twp., Dade Co., MO, Roll M653_617, p. 34, PN 32, 220/220, enumerated 16 Jun 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):

William Snadon	65	M		Farmer	3000	14,000	Virginia
James Snadon	40	M		"			Kentucky
Alexander "	32	M		"		300	"
William   "	27	M		"			"

7.  1870 Census Every-Name-Index/Images (online at Ancestry.com):  William Sr. not found, nor William Jr., nor James, but we do find son, Alexander, living in South Twp., Dade Co., MO, married with two young children and rather well to do, so it appears he has inherited his father's estate.

8.  Abstract of will (online in the Archives of the KYTODD-L mailing list at RootsWeb.com).  Kentucky Family Records - Volume VIII, pp. 48-51, "Abstract of Some Early Wills, Todd County, KY, Will Book A."  (The first date is the date the will was signed, the second date is the date the will was recorded, which is done after the testator is deceased):

THOMPSON, John. 25 Oct 1816. Dec 1816. Wife: Sophia. Daus: Jane Snowden, Sophia, Nancy, Isabella, Polly McFarin. Sons: John, Alexander, Robert, James. Wit: Finis Ewing, Thomas Bryan, George Snoden.

9.  James Taylor Killebrew.  1999.  County Court Order Book "F," Parts 1 & 2 [but not 3], Christian County, Kentucky, for the years 1819-1825.  County Genealogical Society (1101 Bethel St., Hopkinsville, KY 42240).  First column is the page number in Killebrew; second column is the page number in Court Order Book F.

p.	p.	Date	Motions
113	164	2 Dec 1816	The last will and testament of John Thompson deceased was produced in Court and proven by the oaths of Thomas Bryan and George Snowden and ordered to be recorded and on the motion of Robert Thompson and Sophia Thompson executor and Executrix of the last will and testament of Jno. Thompson deceased who made oath as the law directs certificate of probate is granted them in due form of law on the estate of said John Thompson deceased whereupon
114			they entered into an acknowledged bond with George Snowden, Wm. Greenfield and John Gorin their securities conditioned as the law requires.

 
10.  Email from Brad Segers.