1.  Marriage Record:

2.  1860 Census Every-Name-Index/Images (online at Ancestry.com, Image #13 of 67 — our subject is indexed "Wrrin h Hoskins"):  North Chili P.O., Webster, Monroe Co.., NY, Roll M653_786, p. 529, PN 13, 97/97, enumerated 6 Oct 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):

Eli Hoskins	56	M		Farmer	4000	1800	New York
Elizabeth	47	F					Do
Worrin H	27	M		Farm Labourer			Do
Loi??s	25	F		Do			Do
Antinette Jones	22	F		Servant			Do
Charles W	8	M					Do
Catharine	3	F					Do
Agnes	8/12	F					Do

Eli & Elizabeth are Warren's parents.

3.  1870 Census Every-Name-Index/Images (online at Ancestry.com, Image #4 of 58 — our subject is indexed "Harkins"):  Webster P.O., Ontario Co., Wayne Co., NY, Roll M593_1112, p. 318B, PN 4, 25/25, enumerated 20 Jun 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):

Wall Elisha M	68	M	W	Farmer	5000	1500	Vermont
____ Katie	70	F	W	Keeping House			New York
____ Ebenezer	32	M	W	Farmer			New York
Haskins Warren	37	M	W	Farm Laborer			New York
_______ Louis	35	F	W	Keeping House			New York
_______ Lillie	7	F	W	At School			New York
_______ Harriet	5	F	W	At School			New York

"Louis" should obviously be "Lois."  Elisha & Katie are Lois's parents.

4.  1880 Census Every-Name-Index/Images (online at Ancestry.com, Image #5 of 28):  Lansing Twp., Ingham Co., MI, Roll T9_582, p. 307C, PN 7, SD 3, ED 126, 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

15

21

24

25

26

44

45

Hoskins Warren

W

M

47

/

Farmer

NY

NY

NY

Hoskian Lois

W

F

47

Wife

/

Keeps House

Ague

NY

VT

NY

Hoskins Lilly

W

F

17

Dau

/

Does housework

NY

NY

NY

Hoskins Harriett

W

F

15

Dau

/

at School

/

NY

NY

NY

Hoskins Charles

W

M

14

Nephew

/

at School

/

OR

NY

OR

Glosser Cyrus

W

M

26

Boarder

/

works on farm

OH

PA

OH

HOSKINS'es born in Oregon are very rare, and this one has to be Charles Arthur HOSKINS, the orphaned son of Charles HOSKINS, whom I believe to be Warren's first cousin, making Charles Arthur's relationship to Warren that of "first cousin once removed."  Back then, people used the terms, "nephew" and "cousin" (etc.), much more loosely than we do today, and in any case, there's no way the enumerator would have entered his true relationship, even if he had known how to describe it.