— born in Madison or Marion Twp., Fayette Co., OH:
  1.  (Daughter A) STROPE, b. 1824
  2.  (Daughter B) STROPE, b. 1825
  3.  John STROPE, b. 1826/7
  4.  Peter STROPE, b. 30 Jan 1829
  5.  Sarah STROPE, b. 1830/1
  6.  William STROPE, Jr., b. 1832/3
  7.  Elizabeth STROPE, b. 1837/8

— born in Marion Twp., Fayette Co., OH:
  8.  Martha STROPE, b. 1840 or 1841/2
  9.  Lafayette STROPE, b. 1843/4 or 14/17 Mar 1845 
10.  Marion STROPE, b. 1845/6 
11.  Nancy A. STROPE, b. 1848/9; d. by 1860
12.  (Son) STROPE, died young

William is said to have had this son:
.  Boston STROPE, b. 1823/4 or 1825/6 
but there is no son this age in William's household in the 1830 or 1840 censuses.

Could these be the children of son, Peter STROPE?  Peter was married in 1851, but does not show up in the 1860 census.  Peter's wife was named Eleanor.

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

Strope, William

Blue, Nancy

16 Mar 1824

Fayette Co.

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

Wm. STROPE Spouse: Nancy BLUE Marriage: 16 Mar 1824, Fayette, Ohio Source: Marriage Records, 1810-1909. Ohio. Probate Court (Fayette County)

William STROPE Spouse: Eliza BROWN Marriage: 02 Aug 1854, Morgan, Ohio Source: Marriage Records, 1819-1950. Ohio. Probate Court (Morgan County)

How did William come to marry a woman in Morgan County?  Morgan County is four counties away from Fayette County.

2.  1830 Census Index/Images (online at Ancestry.com; Image #9 of 18 — indexed "Strophe"; extracted by Diana Gale Matthiesen):¤•

1830

OH

Fayette Co.

Madison Twp.

p. 288

Ln. 13

William Strope

200 010 - 020 010

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
2 males	4 or under	1825-1830	= Peter (b. 1828/9) = John (b. 1826/7)
1 male	20-29	1800-1810	= William (b. 1805)
2 females	5-9	1820-1825	= Daughter B (b. 1825) = Daughter A (b. 1824)
1 female	20-29	1800-1810	= Nancy (b. 1808)

The only way Nancy could have had two daughters between 1824 and 1825 would have been if she was pregnant when she married and/or if she had twin girls with her first pregnancy, but the latter seems not to have been the case because the girls appear not to have been the same age.  The mention in William's eulogy (see below) to him having married "early in life" may be a veiled reference to him having had to have gotten married at an unusually young age.

3.  1840 Census Index/Images (online at Ancestry.com, Image #3-4 of 10 — indexed "Stroop"; extracted by Diana Gale Matthiesen):¤•

1840

OH

Fayette Co.

Marion Twp.

pp. 13B-14A

Ln. 17

Wm Stroap

120 010 - 111 110

0100000

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	4 or under	1835-1840	= William Jr (b. 1832/3)
2 males	5-9	1830-1835	= Peter (b. 1828/9) = John (b. 1826/7)
1 male	20-29	1810-1820	= William (b. 1805)
1 female	4 or under	1835-1840	= Elizabeth (b. 1837/8)
1 female	5-9	1830-1835	= Sarah (b. 1830/1)
1 female	10-14	1825-1830	= Daughter B (b. 1825)
1 female	15-19	1820-1825	= Daughter A (b. 1824)
1 female	20-29	1810-1820	= Nancy (b. 1808)
1	person employed in agriculture

Most everyone is tallied off one age-class, but this record has to be our family.

4.  1850 Census Index/Images (online at Ancestry.com; Image #1 of 21 — indexed "Strape"):  Marion Twp., Fayette Co., OH, p. 51A, 161/161, enumerated 27 Sep 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):¤•

William Strope	45	M		Farmer	1200	Pa
Nancy      "	42	F				Ohio
John       "	23	M		Laborer		"
Peter      "	21	M		"		"
Sarah      "	19	F				"
William    "	17	M		Laborer		"
Elizabeth  "	12	F				"
Martha     "	10	F				"
Lafayette  "	6	M				"
Marion     "	4	M				"
Nancy A    "	1	F				"

Living next to Solomon VINCENT.

5a.  1860 Census Index/Images (online at Genealogy.com, Image #2 of 22):  New Holland P.O., Marion Twp., Fayette Co., OH, Roll 959 (Book 1), p. 375B, PN 126, 890/891, enumerated 26 Jun 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):¤•

William Strope	55	M		Farmer	5700	665	Pennsylvania
Martha     "	18	F					Ohio
Lafayette  "	16	M					"
Marion     "	14	M					"

It appears Eliza is not living with her husband (see next source).  But why not?

5b.  1860 Census Index/Images (online at Genealogy.com, Image #19 of 22):  Bloomingburg P.O., Marion Twp., Fayette Co., OH, Roll 959 (Book 1), p. 384A, PN 143, 999/1004, enumerated 30 Jun 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):

Elizabeth McLaw	65	F		House Keeper		200	Delaware
Nancy Thompson	15	F					Ohio
Eliza Strope	46	F					"
Sarah H  "	8	F					"

Sarah was born before William & Eliza married, so, if she's not William's niece, she must be Eliza's daughter from a prior marriage, which would mean BROWN is Eliza's married name, not her maiden name.  Also, William already had a daughter, Sarah, born 1830/1, and this Sarah was born after Nancy BLUE died, but before he married Eliza.  Where is the Eleanor who shows up in 1870?

6.  1870 Census Index/Images (online at Genealogy.com, Image #9 of 20):  Pancoastburg P.O., Marion Twp., Fayette Co., OH, Roll 1199 (Book 1), p. 504A, PN 9, 65/66, enumerated 17 Jun 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):¤•

Strope William	65	M	W	Farmer	4104	1015	Pennsylvania
______ Eliza	56	F	W	Keeping House			Ohio
______ Marion	23	M	W	Work on Farm			Ohio
______ Elener	17	F	W	Sewing for Family			Ohio
______ Dora	6	F	W				Ohio

Who is Elener? Where was she in 1860?  Is the Elener here the Sarah H. in 1860?  That is, was "Elener" a mis-hearing of "Helena" or vice-versa?  Dora is William's granddaughter.

7.  1880 Census (indexed at FamilySearch.org; page image online at Ancestry.com, Image #10 of 20):  Marion Twp., Fayette Co., OH, Roll 1014, p. 551B, PN 10, SD 5, ED 55, enumerated 14 Jun 1880, official enumeration date 1 Jun 1880 (extracted by Diana Gale Matthiesen).  This enumerator did not use dwelling and family numbers, so you just have to guess where one household ends and the next begins.¤•

1880:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).
3	4	5	6	8	9	13	21	24	25	26
Strope William	W	M	75	Husband		Farmer		Penn	Penn	Penn
"   Eliza	W	F	59	Wife		House Keeper		O	O	O
"   Dora	W	F	18	Dau	/	House Keeper	/	O
Powell Geo	W	M	18	Servt	/	Farm Hand	/	O	O	O

Eliza is fibbing about her age (she's 66).  Dora is William's granddaughter.

8.  R.S. Dill.  1881.  History of Fayette County, together with Historic Notes on the Northwest and the State of Ohio.  Odell & Mayer, Publ., Dayton, OH (online at Genealogy.com; Borderbund CD-450):

p. 886

The following obituary was read by Rev. Mr. Davis, pastor of New Holland Methodist Episcopal Church, at the funeral of an esteemed pioneer of Marion, Mr. William Strope: William Strope was born in the State of Pennsylvania, May 1, 1805; died in New Holland, Ohio, at two o'clock on the morning of July 13, 1881, aged seventy-six years, two months, and twelve days. He came to Ohio when about eight years old, and for about sixty years, until within a few months of his death, was a resident of Marion Township, Fayette County. He removed to New Holland, where he is well known, a few months ago, expecting restfully and peacefully to spend there the last few years of his life.  But years longer were not for him, but instead months of unrest and pain and the breaking down of his remarkably vigorous constitution. Mr. Strope was twice married; first, early in life, when only about seventeen years of age, to Miss Nancy Blue, who died in 1848; the second time, in 1854, to Eliza Brown, his now bereaved widow.  He was the father of twelve children, six sons and six daughters, and twenty-two grand-children.  Three sons and three daughters preceded him in death. As testimony to the esteem in which Mr. Strope was held by his neighbors, as an honorable and upright citizen, I mention the fact that for thirty-eight years he held the office of justice of the peace in the township in which he lived.  For a number of years he was an acceptable member of the order of Masons.  He was never a member of any church and was somewhat reticent on that subject, except a few expressions toward the last...

The rest of the piece has no genealogical significance — what a waste when the writer could have, in far fewer words, named William's parents and children!

9.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).  One file contains this notation:

William came to Chillicothe Ohio in 1812 from Pennsylvania with his father, Henry Strope.  William was a Justice of the Peace in Marion TWP, Fayette County for over thirty years as well as the town assessor and trustee.