David is said to have died 30 Dec 1900, but he was alive for the 1910 census.

1.  Marriage Record:

2.  1860 Census Images (online at Genealogy.com; Image #5 of 24):  Mount Union P.O., Brady Twp., Huntingdon Co., PA, Roll 1115 (Book 1), p. 59, PN 80, 563/558, enumerated 23 Jul 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):

David Borin	34	M		Laborer		80	Pa
Zala A  "	27	F					"
Clara   "	7	F					"
Martha  "	4	F					"

"Zala" could be Zulu, Zalu, or Zula.  She is called "Zelean" in the 1850 census.

3.  1870 Census Index/Images (online at Genealogy.com):  can't find, at least not with this kludge of a search engine (if only Genealogy.com had a decent search engine, I could probably find him in minutes!).  I did a page-by-page search of Henderson, Union, and Brady Twps. (the last being the location of Mill Creek), Huntingdon Co., PA; Patterson Borough, Juniata Co., PA; North and South Schuylkill Twps. (location of Patterson, a.k.a., Brockton), Schuylkill Co., PA; and St. Mary's Borough, Elk Co., PA, but did not find him.  I did find Michael BORING (æ 43, b. MD, wife Rebecca) in Union Twp., Huntingdon Co., PA (p. 818B).

4.  LDS.  Family Search: Census Records: 1880 United States (online at FamilySearch.org):

Census Place: Dewark, Northumberland, Pennsylvania
Source: FHL Film #1255164; NARA Film #T9-1164; Pg 196D
	Relation	Sex	Marr	Race	Age	Birthplace	Occupation	Fa	Mo
David BORING	Self	M	M	W	53	MD	Work On R. R.	MD	MD
Zaliah BORING	Wife	F	M	W	45	PA	Keeping House	OH	OH
Alvaretta BORING	Dau	F	S	W	23	PA	Dress Maker	MD	PA
Mary L. BORING	Dau	F	S	W	18	PA	Teaching School	MD	PA
Harry F. BORING	Son	M	S	W	12	PA	At Home	MD	PA

It's "Dewart," not "Dewark."  In three out of four censuses, David gave his birthplace as PA.  "Zaliah's" parents were born in PA.

5.  1890 Census:  the 1890 Census Population Schedules were destroyed.

6.  1900 Census Index/Images (online at Genealogy.com; Image #9 of 29 — indexed "Danniel Boring"):  Front Street, Mifflinburg Borough (East Ward), Union Co., PA, p. 260A, SN 5, SD 10, ED 196, 6 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	26	27
*	101	115	Boring David	Head	W	M	Apr 1826	74	M	48			PA	PA	PA	Foreman PRR	10	Y	Y	Y	O	F	H
			______ Juliah Ann	Wife	W	F	May 1833	67	M	48	5	2	PA	PA	PA			Y	Y	Y
			Shook William S	Son in law	W	M	Feb 1859	41	M	18			PA	PA	PA	Jeweler	0	Y	Y	Y
			_____ Clara A	Daughter	W	F	Nov 1853	46	M	18	0	0	PA	PA	PA			Y	Y	Y
*Front Street E Ward

7.  1910 Census Index/Images (online at Genealogy.com; Image #4 of 34):  Chestnut Street, Mifflinburg Borough, Union Co., PA, Roll 1423 (Book 1), p. 189B, SN 2B, SD 13, ED 170, enumerated 18 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

23

24

25

26

27

28

*

63

64

Boring, David

Head

M

W

83

M1

58

PA

PA

MD

Eng

None

Y

Y

O

F

H

______, Zariah A

Wife

F

W

76

M1

58

5

3

PA

PA

OH

Eng

None

Y

Y

Shook Clara A

Dau

F

W

55

M1

28

1

0

PA

PA

PA

Eng

None

Y

Y

_____ William S

Son-in-law

M

W

50

M1

28

PA

PA

PA

Eng

Jeweler

Own Shop

Emp

Y

Y

Boring Martha J

Granddau

F

W

7

S

PA

PA

PA

Eng

None

Y

*Chestnut Street

8.  1920 Census Index/Images (online at Ancestry.com):  not found.

9.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).  Says David was born in Carroll Co., MD.  Has obituary of David.