1.  Marriage Record:

2.  1850 Census Every-Name-Index/Images (online at Ancestry.com, Image #17 of 38):  Greenwood Twp., Juniata Co., PA, Roll M432_786, p. 310B, 2025/2055, enumerated Nov 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):

James Cox	37	M		Millwright		Penna
Cath Cox	22	F				"
Wm Cox	3	M				"
Infant	2/12	F				"

3.  1860 Census Every-Name-Index/Images (online at Ancestry.com, Image #2 of 16):  Richfield P.O., Greenwood Twp., Juniata Co., PA, Roll M653_1119, p. 614, PN 208, 1446/1, enumerated 30 Jul 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):

James Cox	52	M		Farmer	3500	1300	Penna
Cath Cox	37	F					"
Wm C	12	M					"
Eli	10	M					"
Paul	7	M					"
Sarah A	5	F					"
Henrietta	3	F					"
Julianna	3/12	F					"
Susanna	3/12	F					"

4.  1870 Census Every-Name-Index/Images (online at Ancestry.com, Image #10 of 19):  Richfield P.O., Greenwood Twp., Juniata Co., PA, Roll M593_1353, p. 382B, PN 10, 53/53, enumerated 24 Aug 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):

Cox James	62	M	W	Farmer	12500	800	Pa
Kate	46	F	W	Keeping house			Pa
William	22	M	W	F $			Pa
Elias	19	M	W	"			Pa
David	15	M	W				Pa
Sarah	14	F	W				Pa
Henrietta	13	F	W				Pa
Julian	10	F	W	Twins			Pa
Susan	10	F	W	"			Pa
May	6	F	W				Pa

This enumerator used the dollar sign a lot, and I have no idea what it was intended to represent, but surely William and Elias were farm laborers.

5.  1880 Census Every-Name-Index/Images (online at Ancestry.com, Image #6 of 12):  Greenwood Twp., Juniata Co., PA, Roll T9_1137, p. 355B, PN 6, SD 7, ED 134, enumerated 4 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

13

21

24

25

26

45

48

Cox James S

W

M

72

/

Farmer

PA

PA

PA

___ Catharine

W

F

54

Wife

/

Keeping house

PA

PA

PA

___ Susan

W

F

19

Dau

/

At home

PA

PA

PA

___ Mary J

W

F

16

Dau

/

At home

/

PA

PA

PA

Ferguson Julia

W

F

19

Dau

/

At home

PA

PA

PA

Listed next to son, William C. COX (æ 32, b. PA, wife Emma S.).

6.  1890 Census:  the 1890 Census Population Schedules were destroyed.

7.  1900 Census Every-Name-Index/Images (online at Ancestry.com, Image #10 of 12):  Greenwood Twp., Juniata Co., PA, Roll T623_1417, pp. 65A-65B, SN 5, SD 12, ED 116, enumerated 8 Jun 1900, official enumeration date 1 Jun 1900 (extracted by Diana Gale Matthiesen):

1900:  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	13	14	15	19	20	22	23	24	25	27
89	92	Cox James S	Head	W	M	Nov 1807	92	M	50			PA	PA	PA	Wheelwright	12	Y	Y	Y	R	H
[next page]
		___ Catharine	Wife	W	F	Dec 1823	76	M	50	8	8	PA	PA	PA	Keeping House		Y	Y	Y

Living with their son, Paul T. COX (b. Oct 1852, PA, wife Sarah C.).

8.  1910 Census Index/Images (online at Ancestry.com):  not found.

.  A.L. Guss.  1886.  "Chapter XXI: Greenwood Township." Pages 885-891 in F. Ellis & A.N. Hungerford, eds.  History of That Part of the Susquehanna and Juniata Valleys Embraced in the Counties of Mifflin, Juniata, Perry, Union and Snyder in the Commonwealth of Pennsylvania.  Everts, Peck & Richards, Philadelphia. 

... The Seven Star Tavern was built in 1818 by Peter Stroup.  It has been kept by several, and since 1860 has been kept by Thomas COX... SCHOOLS.—The earliest school-house said to have been in the township was built of logs on the Stroup farm, in 1788, and taught by ___ Elder.  About 1810 a house was built at the Seven Star Tavern, in which school was taught by Archibald Steward and Peter Dawson (who was blind in one eye and very much of a humorist), William McComb and his wife, Frank Luke, Samuel Dimm and Andrew Stroup. In 1814 a school-house was built near Cargill's mill (now Dimm's), not far from the present one.  In 1828 a house was erected near where James Cox now lives, which was used until the school system was accepted, in 1836.  The township at present has four schools,— Dimm's, Wilt, Dressler, and Ferguson,— which contain one hundred and forty-eight pupils.

.  Email from Ron Stroup.