— born in Alexander Twp., Benton Co., MO:
6.  John Franklin THOMASON, b. 1843/4 — or Aug 1846? 
7.  Clarissa THOMASON, b. 1844/5 

1a.  Hall County, Georgia, Marriages from 1819 to 1850 (online at GenealogyLibrary.com).  On p. 28:

THOMASON, Garrison

GIBSON, Louisa

10/06/1822

The name "Garrison THOMASON" is so unique, the probability that there were two of them, both born in Georgia at about the same time, is just about nil.

1b.  Jordan R. Dodd, ed.  1993.  Kentucky Marriages:  Early to 1850.  Liahona Research, Orem, UT (Broderbund CD-229):

Thomson, Garrison

Barnett, Lucinda

3 Nov 1833

Christian Co.

1c.  LDS.  Family Search: Internet Genealogy Service:  IGI - International Genealogical Index (online at FamilySearch.org):

William A. COX Spouse: Sarah THOMASON Marriage: 24 Jan 1861, Benton, Missouri Source: patron submission

2.  1840 Census Index and Digital Images (online at Ancestry.com; Image #87-88 of 98 — mis-indexed as "Guirrson Thommason"; extracted by Diana Gale Matthiesen):

1840

KY

Christian Co.

pp. 232B-233A

Ln. 18

Garrison Thommason

300 011 - 010 010

0200000

no slaves

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
3 males	4 or under	1835-1840	= Thomas (b. 1839) = James (b. 1839) = George (b. 1837)
1 male	20-29	1810-1820	= ?
1 male	30-39	1800-1810	= Garrison (b. 1802/06)
1 female	5-9	1830-1835	= Nancy (b. 1835)
1 female	20-29	1810-1820	= Lucinda (b. 1812/14)
2	persons employed in agriculture

3.  1850 Census Index/Images (online at Ancestry.com; Image #11-12 of 18 — images misplaced under the label, Tom Twp.):  Alexander Twp., Benton Co., MO, pp. 296B-297A/590-591, enumerated 22 Oct 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):

322	322	Rial P Means	37	M	Farmer		Illinois
		Lucinda Means	38	F			Kentucky
		Nancy A Means	15	F			Do
		George B Means	13	M			Do
		James Means	11	M			Do
		Thomas Means	11	M			Do
		Sarah Means	8	F			Do
		John F Means	6	M			Missouri
		James M Means	13	M			Illinois
[next page]
323	323	Eliza Means	8	F			Missouri
		Amanda   Do	6	F			Do
		Claricia Do	5	F			Do
		William  Do	2	M			Do

Eliza should not have been given new dwelling and family numbers just because she started a new page.  The first six children listed, plus Clarissa, are Garisson & Lucinda's.  James M, Eliza, and Amanda are Royal's children with his first wife.  William would appear to be the only child born of Royal & Lucinda.

4.  1860 Census Images (online at Ancestry.com; Image #12 of 15):  Warsaw P.O., Township 39, Range 23 [in Alexander Twp.], Benton Co., MO, p. 246, PN 22, 148/146, enumerated 12 Jun 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen).   Secondary sources give the birthplace of our subjects' children as "Warsaw," but that is not where they lived.  They were farmers; they lived out in the country, not in the city of Warsaw.  The "P.O." was not where they lived, it was where they went to pick up their mail, and every household in Benton County gave Warsaw as its post office.  Note that the "township" in the "township and range" designations of the PLS (Public Land System) are not the same thing as the civil divisions of a county known as "townships."  "T39N.R23W" was in Alexander Township.

Lucind Means	46	F		Farmer Tent		960	Ky
Thomas	21	M		F L			"
James	21	M		F L			"
Sarah	17	F		Domest			"
John	15	M		F L			Mo
Clarissa	13	F					"
William	11	M					"
Eliza Means	16	F					"
Amanda	14	F					"

Lucinda has shaved two years off her age.  The first five children are Garrison & Lucinda's.  William is Lucinda's son with her second husband, Royal MEANS.  Eliza and Amanda are Royal's children by his first wife.  Living next door to William & Jane COX and their son, William A. COX, who will next year marry Lucinda's daughter, Sarah.

5.  1870 Census Images (online at Ancestry.com; Image #14 of 293):  Quincy P.O., Alexander Twp., Benton Co., MO, p. 221B, PN 14, 99/99, enumerated 6 Jul 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):

Mains Loucinda	53	F	W	Keeping house	500	422	Kentucky
Thomason Claricy	23	F	W	at home			Kentucky
Mains William	21	M	W	Farmer			Missouri

Lucinda has shaved five years off her age.  Clarissa was born in Missouri.  William is Lucinda's son by her second husband.  Living next door to Lucinda's son, John Franklin THOMASON. 

6.  Emails from Robert Stokes.

7.  Broderbund.  World Family Trees.  Vol. 10, Tree 3066.  Has Garrison born in 1802 in GA; has Lucinda born in 1814 and deceased in 1846.  The dates for Lucinda are definitely incorrect.