According to son John's death certificate, Nancy's maiden name was FERGISON.  A file at WorldConnect shows her maiden name as SPRANGE.  It's possible that Nancy had a prior marriage and that  FERGUSON is her maiden name and SPRANGE the surname of her first husband, or vice versa.  The fact that she is 23 years older than her first child with Joseph also makes it possible she was married earlier.

1.  Marriage Record:

2.  1840 Census Index/Images (online at Ancestry.com, Image #9 of 18; extracted by Diana Gale Matthiesen):¤•

1840

OH

Crawford Co.

Bucyrus Twp.

Roll 388

pp. 6

Ln. 17

Rasey Joseph

100 001 - 100 010

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	4 or under	1835-1840	= John (b. 1835)
1 male	30-39	1800-1810	= Joseph (b. 1801/2)
1 female	4 or under	1835-1840	= Hannah (b. 1837/8
1 female	20-29	1810-1820	= Nancy (b. 1811/2)

This enumerator took no occupation information.  Listed three lines above Joseph's brother, Wooster RASEY.

3.  1850 Census Every-Name-Index/Images (online at Ancestry.com, Image #18 of 22):  Pitt Twp., Wyandot Co., OH, Roll M432_741, p. 236B, 129/1019, enumerated 23 Sep 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):¤•

Joseph Rasey	48	M		Farmer		NY
Nancy    "	38	F				"
John     "	15	M		Laborer		O
Hannah H "	12	F				"
William  "	9	M				"
Sarah J  "	7	F				"

4.  1860 Census Every-Name-Index/Images (online at Ancestry.com, Image #20 of 23):  Little Sandusky P.O., Pitt Twp., Wyandot Co., OH, Roll M653_1054, p. 545B, PN 184, 1298/1316, enumerated 18 Aug 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):•

Joseph Racy	60	M		Farmer	100	50	NY
Nancy	45	F					"
Wm	19	M					O

Listed next to Jacob & Susannah BREWER, parents of two of our subjects' children's spouses.

5.  1870 Census Every-Name-Index/Images (online at Ancestry.com, Image #10 of 17):  West Hope P.O., Monroe Twp., Henry Co., OH, Roll M593_1221, p. 338B, PN 10, 67/67, enumerated 29 Jun 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):

Racey Joseph	73	M	W	Farming	600	400	New York
_____ Nancy	50	F	W	Keeping House			New York
_____ William	28	M	W	Farm Laborer			Ohio

Listed next to Joseph's brother, John RACEY.

6.  1880 Census Every-Name-Index/Images (online at Ancestry.com, Image #9 of 18):  Marseilles Twp., Wyandot Co., OH, Roll T9-1079, p. 612A, PN 9, SD 1, ED 171, enumerated 7 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	24	25	26
90	94	Rasey Joseph	W	M	78			/	Farmer	NY	MA	NY
		_____ Nancy	W	F	69	Wife		/	Keeping house	NY	NY	NY
		_____ William	W	M	39	Laborer	/			OH	NY	NY

7.  1890 Census:  the 1890 Census Population Schedules were destroyed.

8.  1900 Census Every-Name-Index/Images (online at Ancestry.com):  not found.

9.  LDS.  Family Search: Internet Genealogy Service:  IGI - International Genealogical Index (online at FamilySearch.org):  a file there show's Joseph's wife's given name as, "Thankful."

10.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).

11.  Email from descendant:  The informant on son John C.'s death certificate was John's son, Ira, who gave Nancy's surname as FERIGSON (born in NY).