Elizabeth is said to have married John M. KEARNS, but the Elizabeth STROUP living as wife of John KEARNS in the 1850 census was born in 1791 and is our subject's sister, not his daughter — unless both Elizabeth's happened to marry men of the same name.

1.  Marriage Records:

2.  1820 Census Index and Digital Images (online at Ancestry.com; Image #1 of 2; extracted by Diana Gale Matthiesen):¤•

1820

PA

Mifflin Co.

Decatur Twp.

Roll -

p. 204

Ln. 6

John Stroup

110200-10100-0-100

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	9 or under	1810-1820	= William (b. 1817)
1 male	10-15	1804-1810	= ?
2 males	19-25*	1794-1801	= Frampton? (b. 1797/8) = John (b. 1793)
1 female	9 or under	1810-1820	= Catharine (b. 1819)
1 female	16-25	1794-1804	= Margaret (b. 1800)
1	person engaged in agriculture
*In the 1820 Census, the third column is age class 16-18 and the fourth column is age class 16-25; therefore, any individual in column three is duplicated in column four.  By subtracting the number in column three from the number in column four, you can create an age class "19-25."

John is in the wrong age class.  The teenage male is too old to be their son.  The other adult male may be John's idiot brother, Frampton.  Listed two lines from John's father, Philip STROUP; and, in the other direction, listed six lines from John's brother, William STROUP. 

3.  1830 Census Index and Digital Images (online at Ancestry.com; Image #1 of 8; extracted by Diana Gale Matthiesen):¤•

1830

PA

Mifflin Co.

Decatur Twp.

p. 493

John Stroup

Ln. 2

001 112 - 212 010

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	10-14	1815-1820	= William (b. 1817)
1 male	15-19	1810-1815	= ?
1 male	20-29	1800-1810	= ?
2 males	30-39	1790-1800	= Frampton? (b. 1797/8) = John (b. 1793)
2 females	4 or under	1825-1830	= Henrietta (b. 1828) = Sarah (b. 1826)
1 female	5-9	1820-1825	= Margaret (b. 1824)
2 females	10-14	1815-1820	= Elizabeth (b. 1823) = Catharine (b. 1819)
1 female	20-29	1800-1810	= Margaret (b. 1800)

As both Margaret and Elizabeth survived to marry, it looks like one of them must be in the wrong age class.  With all those daughters and only one son, we would expect some hired farm hands in the household.  Listed next to John's father, Philip STROUP.  The other adult male may be John's idiot brother, Frampton. 

4.  1840 Census Index and Digital Images (online at Ancestry.com; Image #1-2 of 8; extracted by Diana Gale Matthiesen):¤•

1840

PA

Mifflin Co.

Decatur Twp.

pp. 62A-62B

Ln. 18

John Stroup

200 010 100 - 012 100 100

_______

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
2 males	4 or under	1835-1840	= David (b. 1838/9) = Martin (b. 1836/7)
1 male	20-29	1810-1820	= William (b. 1817)
1 male	40-49	1790-1800	= John (b. 1793)
1 female	5-9	1830-1835	= Sophia (b. 1830)
2 females	10-14	1825-1830	= Henrietta (b. 1828) = Sarah (b. 1826)
1 female	15-19	1820-1825	= Margaret (b. 1824)
1 female	40-49	1790-1800	= Margaret (b. 1800)

Listed next to John's half-brother, Simon STROUP, on one side; and, on the other side, listed two lines from brother, William STROUP. 

5a.  1850 Census Every-Name-Index/Images (online at Ancestry.com; Image #3 of 26):  Decatur Twp., Mifflin Co., PA, p. 306A, 20/20, enumerated 9 Dec 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):¤•

John Stroup	57	M		Farmer	5000	Pa
Susanna  "	53	F				Pa
Martin L "	13	M				Pa
David A  "	11	M				Pa
John L   "	9	M				Pa
Matilda Graham	22	F				Pa
Frampton Stroup	52	M				Pa	Idiot

Susanna is our subject's second wife and step-mother to John's children.  Matilda is very likely Susanna's daughter from a prior marriage.  Frampton is John's brother.  They are listed two households from John's brother, Simon STROUP. 

5b.  1850 Census Every-Name-Index/Images (online at Ancestry.com, Image #22 of 25):  Decatur Twp., Mifflin Co., PA, Roll M432_797, p. 615B, 156/156, enumerated 13 Dec 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):¤•

Henry Bridge	38	M		Farmer	3000	Pa
Catharine "	30	F				Pa
Sophia Stroup	19	F				Pa
Lucinda A "	6	F				Pa

6a.  1860 Census Every-Name-Index/Images (online at Ancestry.com; Image #101 of 424):  Decatur P.O., Decatur Twp., Mifflin Co., PA, p. 99, PN 1, 2/2, enumerated 1 Jun 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):¤•

John Stroup	66	M		Farmer	20,000	1,600	Penna
Susannah "	62	F					"
John L   "	19	M		Farm Labr			"
Mary     "	20	F		Spinster			"
John M   "	1/12	M					"

Mary is John L.'s wife, and John M. is their son — back then, "spinster" was an occupation, not slang for unmarried.  On one side, they are listed next to John's married daughter, Margaret (STROUP) GRIMMINGER; and, on the other side, they are listed two households from John's married daughter, Sophia (STROUP) YEAGER.  John's son, David, is living with his married brother, Martin Luther STROUP (see below).  John's daughter, Lucinda, is living with her married sister, Susan (STROUP) McAULEY (see below).

6b.  1860 Census Images (online at Ancestry.com; Image #104 of 424):  Decatur P.O., Decatur Twp., Mifflin Co., PA, p. 102, PN 4, 27/24, enumerated 4 Jun 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):¤•

Luther Stroup	23	M		Farmer		800	Penna
Caroline  "	22	F					"
John M    "	2	M					"
David     "	21	M		Farmer		150	"
Sophia Lepley	13	F					"

6c.  1860 Census Every-Name-Index/Images (online at Ancestry.com, Image #7 of 67):  Lewistown P.O., Lewistown (East Ward), Mifflin Co., PA, Roll M653_1141, p. 361, 1175/1108, enumerated 29 Jun 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):¤•

John McCauly	27	M		Agent	500	2000	Pa
Susan M  "	24	F					"
Lucinda Stroup	18	F					"

7.  1870 Census Images (online at Genealogy.com; Image #13 of 50):  Lewistown P.O., Derry Twp., Mifflin Co., PA, Roll 1375, p. 303A, PN 13, enumerated 9 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	9	10	11	12	19
81	84	Hoops John R	51	M	W	Country Store	1000	2000	Pennsylvania			/
		_____ Asenath	44	F	W	Keeping house			"
		_____ John W	4	M	W	at home			"
		Stroup Susanna	72	F	W	at home			"	/	/

8.  Samuel Sterrett.  1886.  "Decatur Township."  Chap. XVI, pp. 654-659 in Franklin Ellis, ed. History of That Part of the Susquehanna and Juniata Valleys Embraced in the Counties of Mifflin, Juniata, Perry, Union and Snyder. Philadelphia (online in the archives of USGenWeb):

p. 654	The following is the assessment of Decatur township in 1815, and gives the names of owners of real estate, number of acres and mills in the township at that time... Philip Stroup, 240; William Stroup, 300...
p. 655	The family of Stroup were early settlers in the territory of Derry township (now Decatur).  Philip and William Stroup were warrantees, and their descendants are living in the county. John Stroup, who died December 11, 1867, aged seventy-four years, was of the family, and was born in November, 1793.  After a limited education he began life as a farmer, first working for his father and subsequently renting a farm.  He then, having inherited a portion of the homestead in Decatur township, purchased the remainder, where he resided until his death.  He was also for many years extensively engaged in the purchase and sale of stock.  He was married, in 1817, to Margaret Bair, one of eleven children of Michael Bair and Catherine Bowersox, who was a German descent, and born in York County, Pa.  Her death occurred January 21, 1843.  Their children are William, born November 9, 1817; Catherine, May 16, 1819; John, November 5, 1821; Elizabeth, October 2, 1823; Margaret, September 17, 1824; Sarah, September 5, 1826; Henrietta, December 30, 1828; Sophia K., November 2, 1830; Mary, November 21,1832; Susan H., December 3, 1834; Martin Luther, March 1, 1837; David A., March 21, 1839; John L., September 25, 1841; Lucinda A., December 18, 1842; of whom nine are still living.  Mr. Stroup, as an exemplary and respected citizen, wielded much influence in the community.  Apart from various township offices held by him, he manifested no desire for distinctions of political character.  He was a member and for many years an elder in the Evangelical Lutheran Church in Decatur township. Sarah, daughter of John Stroup, was born on the homestead and married in Lewistown, Pa., on the 19th of January, 1846, to Joseph Mohler.  To them were born eleven children, eight of whom are now living.  Mr. and Mrs. Mohler reside upon their farm in Derry township.  The latter united with the German Baptist Church in 1848, of which she has since been a regular attendant. Sophia K. Stroup was born in Decatur township, and on the 19th of May, 1853, was married, at the house of her sister, Mrs. Bridge, of Decatur township, to John G. Yeager.  After engaging for five years in the business of hotel-keeping in Centre County they returned to Decatur township and resided for three years upon a farm.  They resumed hotel-keeping at Millersburg, Pa., and ultimately removed to the farm now occupied by Mrs. Yeager, in her native township, where Mr. Yeager died on the 13th of August,
p. 656	1867.  The children of Mr. and Mrs. Yeager are Oscar W. and James W., the latter being deceased. Susan H. Stroup, the tenth child of John and Margaret Stroup, was born in Decatur township, and married, on the 11th of October, 1853, to John M. McAuley.  They have six children, three of whom survive.  The present home of Mr. and Mrs. McAuley is at Locke's Mills, Mifflin County. David A. Stroup resided with his father until twenty-four years of age, meanwhile assisting him on the farm.  He has more recently been engaged in the wood and lumber business, though much of his life has been spent as a farmer.  He married, August 6, 1862, Mary E., daughter of Thomas and Mary Kearns.  Of their eleven children, seven are now living. Martin Luther Stroup was born in Decatur township and received limited educational advantages at the public school.  For years he assisted his father on the farm, and, receiving his portion of his father's estate, purchased a farm in the same township.  Having sold this property, he purchased again in Derry township, where he now resides.  He married, October 5, 1857, Caroline, daughter of Jacob Miller, of Schuylkill County, Pa., their children being John M., Sallie, Katy J., Jacob W., Harry B. and Frank M.  Mr. Stroup is a member and served for years as deacon of the Evangelical Lutheran Church of Decatur township. John L. Stroup, also born on the homestead, in Decatur township, was married to Mary Dressher, of Centre County, Pa.  They have had seven children, all of whom, with the exception of a son, McClellan, are now living.  Mr. Stroup has always been engaged in the employment of a farmer and resides at Paintersville, Mifflin County, Pa.  In politics he has been for years a Democrat.

9.  Archives of the STRAUB-L Mailing List (online at RootsWeb.com).

10.  Messages in the Stroup Family Genealogy Forum (online at GenForum.com).

11.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).

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