— born in IL — presumably in Ogle Co., IL:
5.  William H. STROUP, b. 1840/1 or 27 Jan 1842
6.  Jonathan Samuel STROUP, b. 1842/3 or 1 Jan 1844
7.  Louisa J. STROUP, b. 31 Jul 1846
8.  Sarah E. STROUP, b. 22 Nov 1848

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

Jacob STROUP Spouse: Rebecca HOLLENBAUGH Marriage: 05 May 1833, Illinois Source: patron submission

Not only are they not found in the Illinois Statewide Marriage Index, their first child was born in PA, so while this date is probably correct, they were almost certainly married in PA, not IL.

1b.  Illinois Statewide Marriage Index, 1763–1900:  not found.

2.  1840 Census Index/Images (online at Ancestry.com, Image #7-8 of 54 — indexed "Strouf," which it does look like; thank you to Rita Rogers Nowack for alerting me to this record; extracted by Diana Gale Matthiesen):¤•

1840

OH

Clark Co.

Springfield Twp.

Roll 383

pp. 22B-23A

Ln. 26

Jacob Stroup

110 001 - 110 010

0100000

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	4 or under	1835-1840	= Andrew (b. 1837)
1 male	5-9	1830-1835	= George (b. 1833)
1 male	30-39	1800-1810	= Jacob (b. 1807)
1 female	4 or under	1835-1840	= Mary (b. 1839)
1 female	5-9	1830-1835	= Matilda (b. 1835)
1 female	20-29	1810-1820	= Rebecca (b. 1812)
1	person employed in agriculture

3a.  1850 Census Every-Name-Index/Images (online at Ancestry.com; Image #1-2 of 12):  Mt. Morris Village, Ogle Co., IL, Roll M432_123, pp. 12A-12B, 7/7, enumerated 10 Sep 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):¤•

Jacob Stroup	43	M		Farmer		Pa
George    "	16	M				"
Matilda R "	14	F				Ohio
Clara Hedrick	4/12	F				Ill
[next page]
Andrew Stroup	12	M				Ohio
Polly A   "	11	F				Mo
Wm H      "	9	M				Ill
Jonathen  "	7	M				"
Leander   "	4	M				"
Sarah     "	1	F				"

Who is Clara?

3b.  1850 Census Every-Name-Index/Images (online at Ancestry.com; Image #21 of 26):  Mt. Morris Twp., Ogle Co., IL, Roll M432_123, p. 22A, 5/5, enumerated 26 Oct 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):¤•

Jonas Shaffstall	40	M		Mill wright	2500	Pa
[Jonas's wife and children et al.
George Stroup	17	M		Farmer		Pa

George seems to have gotten himself enumerated twice, once with his parents and once here.

4a.  1860 Census Every-Name-Index/Images (online at Ancestry.com, Image #18 of 22):  Mier P.O., Lancaster Precinct, Wabash Co., IL, Roll M653_234, p. 117, PN 117, 848/847, enumerated 12 Jul 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):¤•

Jacob Stroup	50	M		Farmer	500	300	Pa
William  "	21	M					"
Louisea  "	13	F					Ills
Janthan  "	12	M					"
Sarah    "	11	F					"

Listed two households from sons George and Andrew.

4b.  1860 Census Every-Name-Index/Images (online at Ancestry.com, Image #18 of 22):  Mier P.O., Lancaster Pct., Wabash Co., IL, Roll M653_234, p. 117, PN 117, 846/847, enumerated 12 Jul 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):¤•

Philip Keller	60	M		Clockmaker	500	60	Hessan DS G
Louis    "	23	M		Farm Laborer			Wabash
Adam     "	20	M		"     "			"
Margaret "	17	F					"
George Stroup	26	M		Farmer		100	Pa
Elizabeth "	22	F					Wabash
Andrew    "	28	M		"			Pa

Listed two households from George and Andrew's father, Jacob STROUP.

5a.  1870 Census Every-Name-Index/Images (online at Ancestry.com, Image #3 of 38):  Rochester Mills P.O., Coffe Precinct, Wabash Co., IL, Roll M593_286, p. 415A, PN 3, 23/23, enumerated 13 Jun 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):¤•

Stroup George	37	M	W	Engineer	1200	200	Penn
[George's wife and children]
______ Jacob	63	M	W	Farmer		100	Penn

5b.  1870 Census Every-Name-Index/Images (online at Ancestry.com, Image #12 of 30):  Fairview P.O., Madison Twp., Richland Co., IL, Roll M593_272, p. 546B, PN 12, enumerated 7 Jul 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):¤•

1870:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).
1	2	3	4	5	6	7	8	10	11	12	19
92	92	Guyot Adam	27	M	W	Works in BlkSmith Shop	400	Illinois	/	/	/
		_____ Louisa	24	F	W	Keeping house		Illinois
		_____ Charles	1	M	W			Illinois
		Stroup Sarah	23	F	W	Domestic Servant		Illinois

6.  1880 Census Every-Name-Index/Images (online at Ancestry.com, Image #18 of 25):  Leech Twp., Wayne Co., IL, Roll T9_257, p. 197B, PN 18, SD 8, ED 145, enumerated 21 Jun 1880, official enumeration date 1 Jun 1880 (extracted by Diana Gale Matthiesen):¤•

1880:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).

1

2

3

4

5

6

8

9

10

11

13

15

21

24

25

26

171

171

Straup John

W

M

36

/

farm

IL

PA

PA

______ Laura

W

F

28

wife

/

Keeping house

IL

IL

IL

______ Bertie

W

M

5

son

/

/

IL

IL

IL

Staup Jacob

W

M

73

father

/

Retired farmer

old age

PA

PA

PA

7.  Broderbund.  World Family Trees.  Vol. 12, Pedigree #3834.

8.  LDS.  Family Search: Internet Genealogy Service:  AF - Ancestral File (online at FamilySearch.org).

9.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).  A file here says Jacob moved to Will Co., IL, but no STROUP shows up in any census in this county.  If Jacob moved to Will County, he quickly moved on.  A file there also cites a family letter giving Jacob a brother, George, and a sister, Margaret, which supports him being the son of Peter & Rosanna.

10.  Messages posted to the STROUP Surname Board (online at Ancestry.com).