— born in Knox Co., OH:
  6.  Hiram HORN, b. 1821/2
  7.  David HORN, b. 1823; d. 25 Dec 1898, Altamont, Labette Co., KS; bur. Fairview Cemetery, Labette Co., KS; m. 15 Jan 1846, Mt. Vernon, Knox Co., OH, Judith Ann REESER
  8.  Anna HORN, b. 1826/7
  9.  (Daughter C) HORN, b. 1825-30
10.  (Son D) HORN, b. 1825-30
11.  Prudence HORN, b. 1831/2
12.  Benjamin HORN, b. 1832/3

1.  Family Quest Archives:  Ohio Federal Census 1820:  Clark, Coshocton, Gallia, Hocking, Huron, Knox, Lawrence, Meigs, and Monroe Counties.  Heritage Quest CD M33-88 (extracted by Diana Gale Matthiesen).

1820

OH

Knox Co.

p. 139

Benjamin Horne

300010-20010

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
3 males	9 or under	1810-1820	= Son C = Son B = Son A
1 male	26-44	1775-1794	= Benjamin (b. 1791/2)
2 females	9 or under	1810-1820	= Daughter B = Daughter A
1 female	26-44	1775-1794	= Anna (b. 1790/1)

2.  NARA. 1949.  Fifth Census of the United States, 1830, Population Schedules, Volume 9, Roll 134, Ohio.  File Microcopy No. 19.  National Archives, Washington, DC  (Family Quest Archives:  Ohio Federal Census 1830:  Jackson, Jefferson, Knox, Lawrence, and Licking Counties.  Heritage Quest CD M19-134; extracted by Diana Gale Matthiesen).

1830

OH

Knox Co.

Harrison Twp.

p. 220A

Horn Benjamin

121 101 - 210 101

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	4 or under	1825-1830	= Son D
2 males	5-9	1820-1825	= David (b. 1824) = Hiram (b. 1821/2)
1 male	10-14	1815-1820	= Son C
1 male	15-19	1810-1815	= Son B
1 male	30-39	1790-1800	= Benjamin (b. 1791/2)
2 females	4 or under	1825-1830	= Daughter C = Anna (b. 1826/7)
1 female	5-9	1820-1825	= Daughter B
1 female	15-19	1810-1815	= Daughter A
1 female	30-39	1790-1800	= Anna (b. 1790/1)

3.  NARA.  1967.  Population Schedules of the Sixth Census of the United States, 1840, Roll 406, Ohio, Volume 13 (211-412): Knox County.  Microcopy No. 704. National Archives Microfilm Publications, Washington, DC  (Family Quest Archives:  Ohio Federal Census 1840:  Knox County.  Heritage Quest CD M704-406; extracted by Diana Gale Matthiesen).

1840

OH

Knox Co.

Harrison Twp.

p. 274B

Benjamin Horn

011 120 100 - 002 010 100

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	5-9	1830-1835	= Benjamin (b. 1832/3)
1 male	10-14	1825-1830	= Son D
1 male	15-19	1820-1825	= David (b. 1824)
2 males	20-29	1810-1820	= Son C = Son B
1 male	40-49	1790-1800	= Benjamin (b. 1791/2)
2 females	10-14	1825-1830	= Daughter C = Anna (b. 1826/7)
1 female	20-29	1810-1820	= Daughter A
1 female	40-49	1790-1800	= Anna (b. 1790/1)

Prudence is missing.  Could we have her birthdate wrong and might she be Daughter C?  Or did the census-taker simply make a mistake?

4.  Family Quest Archives:  Ohio Federal Census 1850: Knox County.  Heritage Quest CD M432-700:  Harrison Twp., Knox Co., OH, p. 401AB, 2486/2546, enumerated 25 Sep 1850 (extracted by Diana Gale Matthiesen):

Benjamin Horn	58	M	Farmer	3000	Penn
Anna      "	59	F			do
Hiram Horn	28	M	Farmer		Ohio
Anna     "	23	F			do
Prudence "	18	F			do
Benjamin "	17	M	do		do
Mariah   "	6	F			do
Casius Morningstar	2	M			do
Josiah Horn	27	M	Blk Smith		do
Washington "	21	M	Labourer		do

Because of their ordering in the record, it's doubtful that Josiah and Washington are their children (nephews, perhaps?).  It's also doubtful that Mariah is their daughter because Anna is too old to be her mother, and she cannot possibly be Casius's mother for that same reason.  Young children in the home of a mature couple are almost always grandchildren.

5.  LDS.  Family Search: Internet Genealogy Service: Ancestral File.  Gives Anna's surname as ELY.