1.  George W. Wagenseller.  1899.  Snyder County Marriages, 1835=1899.  Wagenseller Publ., Middleburgh, PA (available as facsimile reprint from HigginsonBooks.com):

p. 05	SNYDER COUNTY MARRIAGES, 1868--1888...
p. 86	Mar. 15, by Rev. Haas, John A. Klingler of Salem to Emma Stroab of Kratzerville.

2.  1880 Census Every-Name-Index/Images (online at Ancestry.com):   John A. KLINGLER (æ 14, b. PA) is living in Penn Twp. [location of Salem], son of Enos KLINGLER (æ 50, b. PA) & wife, Elizabeth (æ 40, b. PA).  Emma J. STRAUB (æ 14) is living in Middle Creek Creek Twp., Snyder Co., PA, with her parents (q.v.).  There are no STRAUB/STROUP/etc., at all, living in Kratzerville.

3.  1890 Census:  the 1890 Census Population Schedules were destroyed.

4.  1900 Census Every-Name-Index/Images (online at Ancestry.com, Image #11 of 14):  Union Twp., Union Co., PA, Roll T623_1488 (Book 1), p. 283A, SN 6, SD 10, ED 197, enumerated 19 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	21	22	23	24	25	27	28
272	290	Klingler John	Head	W	M	Nov 1865	34	M	12			PA	PA	PA	Farmer	0		Y	Y	Y	R	F	47
		________ Emma G	Wife	W	F	Sep 1865	34	M	12	1	1	PA	PA	PA				Y	Y	Y
		________ Charles	Son	W	M	Jun 188?	12	S				PA	PA	PA	At school		7	Y	Y	Y

The page was water-damaged, and the ink had run, so my extraction may not be entirely accurate.  Listed between two OLDT families.

5.  1910 Census Every-Name-Index/Images (online at Ancestry.com, Image #3 of 16):  Union Twp., Union Co., PA, Roll T624_1423 (Book 1), p. 212A, SN 2A, SD 13, ED 172, enumerated 19 Apr 1910, official enumeration date 15 Apr 1910 (extracted by Diana Gale Matthiesen):¤•

1910:  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

17

18

19

20

21

22

23

24

25

26

27

28

29

17

18

Klingler John A

Head

M

W

44

M1

22

PA

PA

PA

Eng

Farmer

General Farm

Emp

Y

Y

O

M

F

15

________ Emma J

Wife

F

W

44

M1

22

1

1

PA

PA

PA

Eng

None

Y

Y

________ Charles A

Son

M

W

21

M1

4

PA

PA

PA

Eng

Farm Laborer

Home Farm

W

N

0

Y

Y

________ Bertha M

Dau-in-Law

F

W

19

M1

4

1

1

PA

PA

PA

Eng

None

Y

Y

N

________ Chas A Jr

Grand-Son

M

W

2

S

PA

PA

PA

None

Listed next to an OLDT family.

6.  1920 Census Every-Name-Index/Images (online at Ancestry.com, Image #5 of 10):  Front Street, New Berlin Borough, Limestone Twp., Union Co., PA, Roll T625_1655 (Book 2), p. 215A, SN 3A, SD 14, ED 184, enumerated 21 Jan 1920, official enumeration date 1 Jan 1920 (extracted by Diana Gale Matthiesen):¤•

1920:  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	17	18	19	21	23	25	26	27	28	29
*	fm	59	64	Klingler John	Head	O	F	M	W	54	M	Y	Y	PA	PA	PA	Y	Farmer	General Farm	OA	5
				________ Emma	Wife			F	W	54	M	Y	Y	PA	PA	PA	Y	None
*Front Street

7.  1930 Census Every-Name-Index/Images (online at Ancestry.com, Image #5 of 10):  Front Street, New Berlin Borough, [Limestone Twp.,] Union Co., PA, Roll 2150 (Book 2), p. 233A, SN 3A, ED 60-15, SD 18, enumerated 4 Apr 1930, official enumeration date 1 Apr 1930 (extracted by Diana Gale Matthiesen):¤•

1930:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).
1	3	4	5	6	7	9	10	11	12	13	14	15	16	17	18	19	20	24	25	26	27	28	30	32
*	61	69	Klingler John A	Head	O	R	Y	M	M	63	Wd	22	N	Y	PA	PA	PA	Y	Farmer	General Farm	O	Y	N	1
			Johnson Sadie R	Servant				F	W	51	Wd	18	N	Y	DE	DE	DE	Y	None
*Front Street

Sadie's a "servant" and she has no occupation?  [@$%!]

8.  Linda Libicam.  Everyone in Oliver's Database (online at familyorigins.com).

9.  Archives of the OTT-L Mailing List (online at RootsWeb.com).  Message there says Enos & Elizabeth (OTT) KLINGLER moved to Elkhart Co., IN, some time before 1892.