1.  Anon.  1966.  Marriage Index:  Ohio, 1789-1850.  Liahona Research, Orem, UT (Broderbund CD-400):

Lamb, Peter

Trimble, Mary

25 Apr 1833

Fairfield Co.

2.  1840 Census Index and Digital Images (online at Ancestry.com; Image #9 of 20; extracted by Diana Gale Matthiesen):

1840

OH

Fairfield Co.

Richland Twp.

p. 381B

Ln. 22

Lamb Peter

120 001 - 100 010

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	4 or under	1835-1840	= Thomas (b. 1837/8)
2 males	5-9	1830-1835	= Isaac (b. 1834/5) = William (b. 1832/3)
1 male	30-39	1800-1810	= Peter (b. 1808/9)
1 female	4 or under	1835-1840	= Mary (b. 1839/40)
1 female	20-29	1810-1820	= Mary (b. 1814/5)
1	person employed in agriculture

List was roughly alphabetized.

3.  1850 Census Index/Images (online at Ancestry.com; Image #24 of 41):  Richland Twp., Fairfield Co., OH, p. 398A, 176/183, enumerated 15 Oct 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):

Peter Lamb	41	M		Farmer	4440	O
Mary    "	35	F				O
Willm   "	17	M		Laborer		O
Isaac   "	14	M				O
Thomas  "	12	M				O
Mary E  "	10	F				O
Amelia  "	8	F				O
Peter   "	6	M				O
John    "	4	F				O
Jacob   "	2	M				O

4.  1860

5.  1870

6.  LDS.  Family Search: Census Records: 1880 United States (online at FamilySearch.org):

Census Place: Richland, Fairfield, Ohio
Source: FHL Film #1255014; NARA Film #T9-1014; Pg 281A
	Relation	Sex	Marr	Race	Age	Birthplace	Occupation	Fa	Mo
Polly LAMB	Self	F	M	W	66	OH	Keeping House	PA	PA
Mary E. LAMB	Dau	F	S	W	40	OH	Without Occupation	OH	OH
Amelia LAMB	Dau	F	S	W	38	OH	Music Teacher	OH	OH
Jacob LAMB	Son	M	S	W	30	OH	Farmer	OH	OH