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

Elijah NELSON Spouse: Lucinda STAPLES Marriage: 06 Oct 1833, Jefferson, Missouri Source: Marriage Records, 1825-1951. Jefferson County (Missouri). Recorder of Deeds

Lucinda STAPLES Birth: 22 Jan 1815, Jefferson, Missouri Father: Charles STAPLES; Mother: Elleanor 'Nellis' ROBERTSON Source: patron submission

2.  1840 Census Index/Images (online at Ancestry.com, Image #5 of 5; extracted by Diana Gale Matthiesen):

1840

MO

Jefferson Co.

Valle Twp.

Roll 224

pp. 115

Ln. 11

E K Nelson

210 010 - 000 010

[second page missing]

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
2 male	4 or under	1835-1840	= William (b. 1838/9) = John (b. 1836/7)
1 male	5-9	1830-1835	= Charles (b. 1834/5)
1 male	20-29	1810-1820	= Elijah (b. 1812/3)
1 female	20-29	1810-1820	= Lucinda (b. 1814/5)

3.  1850 Census Every-Name-Index/Images (online at Ancestry.com, Image #149 OF 153):  District No. 42, Jefferson Co., MO, Roll, p. 481A, 1090/1090, enumerated 2 Nov 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):

Lucinda Nelson	35	F				Mo
Elijah H Nelson	37	M	Farmer			Ind
Charles W   "	15	M				Mo
John L      "	13	M				Mo
William J   "	11	M				Mo
Mary J      "	3	F				Mo
Ellen       "	4/12	F				Mo
Francis J Staples	6	F				Mo
Ellen Ballew	56	F				Ky

There's a line from Lucinda to Elijah appearing to suggest she should have been listed after him.  I don't know who Francis J. STAPLES is.

4.  1860 Census Every-Name-Index/Images (online at Ancestry.com, Image #11 of 27):  Hillsboro P.O., Central Twp., Jefferson Co., MO, Roll M653_626, p. 527, PN 11, 73/75, enumerated 21 Aug 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):

Chas W Nelson	25	M		Farmer	1200	100	Mo
Rachael   "	67	F		Do			Ky
Mary Ann  "	28	F					Mo
Wm J      "	21	M		Do			"
Mary J    "	13	F					"
Elleanor	10	F					"

I'll wager Rachael NELSON is Charles's maternal grandmother.  Mary Ann might be Charles's wife, but