1.  Marriage Record:

2.  1850 Census Every-Name-Index/Images (online at Ancestry.com):  John W. STROUP (æ 9, b. PA) is living in Rockland Twp., Venango Co., PA, with his parents (q.v.).  Alena SNYDER (æ 2, b. PA) is living in Bradford Twp. [presumably now Foster Twp. as she was born in Kendall], McKean Co., PA (Roll M432_795, p. 24B), with her parents William SNYDER (æ 50, b. NY) and Fanny (æ 43, b. NY).  William is listed next to his presumed brother, George SNYDER (æ 46, b. NY), who is two households from their presumed mother, Widow Nancy (__?__) SNYDER (æ 85, b. PA), who is living with their presumed sister, Sarah "Sally" (SNYDER) WHITTAKER (æ 38, b. NY).

3.  1860 Census Every-Name-Index/Images (online at Ancestry.com/Genealogy.com):  John M. STROUP (æ 20, b. PA) is living in Tionesta Twp., Venango [now Forest] Co., PA, with his parents (q.v.).  I can't find Allena, but the first 98 pages of Bradford Twp., McKean Co., PA, are missing, both at Ancestry.com and Genealogy.com (along with all of Annin Twp., i.e., the beginning of Roll M653_1138).

2.  1870 Census Every-Name-Index/Images (online at Ancestry.com, Image #17 of 21):  Tionesta P.O., Borough of Tionesta, Forest Co., PA, Roll M593_1344, p. 58A, PN 5, 37/33, enumerated 3 Jun 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):¤•

Stroup John W	29	M	W	Laborer		300	Pennsylvania
______ Allena M	21	F	W	Keeping house			Pennsylvania
______ William	2	M	W				Pennsylvania
Broderick Margaret	19	F	W	Domestic Servant			Pennsylvania

3.  1880 Census Every-Name-Index/Images (online at Ancestry.com, Image #37 of 54):  Kendall Borough, [Foster Twp.,] McKean Co., PA, Roll T9-1154, p. 358A, PN 37, SD 6, ED 91, enumerated 18 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	13	21	24	25	26
337	359	Stroupe John	W	M	38		oil Producer		PA	PA	VA
		_______ Lena	W	F	32	Wife	Keeping house		PA	PA	VA
		_______ Willie	W	M	12	Son		/	PA	PA	PA

4.  1890 Census:  the 1890 Census Population Schedules were destroyed.

5.  1900 Census Every-Name-Index/Images (online at Ancestry.com):  John is deceased and Allena is not found, at least not as STROUP.

6.  Emails from Stephen Straub.

7.  Messages posted to the Snyder Family Genealogy Forum (online at GenForum.com):  a biography of one of George SNYDER's sons indicates the family moved from Sardinia, Erie Co., NY, to Bradford Twp., McKean Co., PA, ca. 1843-45.

8.  Anon.  1890.  History of the Counties of McKean, Elk and Forest, Pennsylvania.  J.H. Beers & Co., Chicago (online at Ancestry.com).  The Borough of Kendall is described as being in Foster Twp., just north of Bradford City (i.e., apparently at the mouth of Kendall Creek where it joins Tunungant Creek).  Foster Twp. was formed from Bradford Twp. in 1880.

9.  Home Town Locator (by HTL, Inc.):  It appears that, today, Kendall Borough is called Kendall Creek and is a mere district of the city of Bradford; Kendall Creek has zip code 16701.