While it is possible that the Polly in the 1850 census was Gurdon's only wife, it is also possible that Gurdon had more than one spouse, the likelihood of which is suggested by there being a ten-year gap between the births of Joshua and Morris.  The date of Gurdon's marriage to Polly would answer this question, so we greatly need their marriage record.

Abigail appears not to be their daughter, but if not, who is she?
?  Abigail HUNTINGTON, b. 1831/2  {18, ??}

1.  LDS.  Family Search: Internet Genealogy Service:  IGI - International Genealogical Index (online at FamilySearch.org).

Gurdon HUNTINGTON Spouse: Mary BROWN Marriage: 19 Dec 1802, <windham>, Windham, Connecticut Source: LDS, sealings for the dead... (i.e., patron submission)

While this record looks promising, there is a Gurdon HUNTINGTON in the 1820 and 1830 censuses of Windham Co., CT, so he would appear to be a different Gurdon.  Also, Polly was a bit young to have married in 1802.

2.  Census Index:  U.S. Selected Counties, 1800 (Broderbund CD-312):  not found.  There were no HUNTINGTONs in Ontario Co., NY (n.b., Genesee Co. was formed from Ontario Co. in 1802/3, then Niagara Co. was formed from Genesee Co. in 1808).

3a.  Census Index:  U.S. Selected Counties, 1810 (Broderbund CD-313).  Please see my WARNINGS regarding use of these CDs.  In this case, Gurdon's data have undergone what's called, in database parlance, a "frame shift."  The data are shifted one digit to the left of where they should be.  See next source for the correct data. 

1810	Huntington, Gurden	NY	Genesee Co.	p. 106	00102-01000
1810	Huntington, John	NY	Genesee Co.	p. 108	50010-00010

3b.  Family Quest Archives:  New York Federal Census 1820:  Essex, Franklin, Genesee, Greene, and Herkimer Counties.  Heritage Quest CD M252-27 (Image #65; extracted by Diana Gale Matthiesen):

1810

NY

Genesee Co.

p. 106

Gurden Huntington

00010-20100

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	26-44	1765-1784	= Gurdon (b. 1783)
2 females	9 or under	1800-1810	= Sarah (b. 1804-10) = Daughter A
1 female	16-25	1784-1794	= Polly (b. 1789/90)

4a.  Census Index:  U.S. Selected Counties, 1820 (Broderbund CD-314):

1820	Huntington, Garden	NY	Genesee Co.	Batavia	p. 17
1820	Huntington, Samuel	NY	Genesee Co.	Pembroke	p. 219
1820	Huntington, Charles	NY	Genesee Co.	Perry	p. 231

These are all the HUNTINGTONs in the county.

4b.  M33-72.

1820

NY

Genesee Co.

Batavia

p. 19

Gurden Huntington

110210-01010

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	9 or under	1810-1820	= Joshua (b. 1811/2)
1 male	10-15	1804-1810	= Son A
2 males	19-25*	1794-1801	= ? = ?
1 male	26-44	1775-1794	= Gurdon (b. 1783)
1 female	10-15	1804-1810	= Sarah
1 female	26-44	1775-1794	= Polly (b. 1789/90)
*In the 1820 Census, the third column is age class 16-18 and the fourth column is age class 16-25; therefore, any individual in column three is duplicated in column four.  By subtracting the number in column three from the number in column four, you can create an age class "19-25."

The two males age 19-25 are too old to be their sons; they could be hired help, boarders, or kin.

5a.  Census Index:  U.S. Selected Counties, 1830 (Broderbund CD-315):

1830	Huntington, Gurdon	NY	Genesee Co.	Batavia	p. 328
1830	Huntington, Abner	NY	Genesee Co.	Covington	p. 173
1830	Huntington, Samuel	NY	Genesee Co.	Pembroke	p. 248
1830	Huntington, Charles	NY	Genesee Co.	Bethany	p. 352
1830	Huntington, Josiah	NY	Genesee Co.	Le Roy	p. 405

These are all the HUNTINGTONs in the county.

5b.  Heritage Quest CD M19-90.

1830

NY

Genesee Co.

Batavia

p. 328A

Gurdon Huntington

110 110 100 - 100 000 100

This film is so scratchy, I haven't a great deal of confidence that I've extracted the numbers correctly.  These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	4 or under	1825-1830	= Gurdon Jr. (b. 1825)
1 male	5-9	1820-1825	= Morris (b. 1821/2)
1 male	15-19	1810-1815	= Joshua (b. 1811/2)
1 male	20-29	1800-1810	= Son A
1 male	40-49	1780-1790	= Gurdon (b. 1783)
1 female	4 or under	1825-1830	= Daughter C
1 female	40-49	1780-1790	= Polly (b. 1789/90)

Living next door to Daniel HOLT, whose wife is their daughter, Sarah. 

6a.  Census Index:  U.S. Selected Counties, 1840 (Broderbund CD-316):

1840	Huntington, Gardner*	NY	Niagara Co.	Somerset	p. 149
*"For the first name in this entry, the person who indexed the record was uncertain about the transcription due to difficulties in deciphering the original records."

6b.  Family Quest Archives:  New York Federal Census 1840:  Niagara County.  Heritage Quest CD M704-311:

1840

NY

Niagara Co.

Somerset

p. 149

Gurd__ Huntington

011 100 010 - 001 100 100

There's a piece of tape over part of the name that, on this image, completely blacks out what's underneath it.  These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	5-9	1830-1835	= George (b. 1830/1)
1 male	10-14	1825-1830	= Gurdon Jr. (b. 1825)
1 male	15-19	1820-1825	= Morris (b. 1821/2)
1 male	50-59	1780-1790	= Gurdon (b. 1783)
1 female	10-14	1825-1830	= Daughter C
1 female	15-19	1820-1825	= Daughter? B
1 female	40-49	1790-1800	= Polly (b. 1789/90)

The older teenage girl was not in the household in 1830, so either the census-taker made a mistake (by missing her in 1830) or she is not their daughter.  Also in the county:  son, Joshua HUNTINGTON, and son-in-law, Daniel HOLT, whose wife if their daughter, Sarah. 

7a.  Census Index:  U.S. Selected Counties, 1850 (Broderbund CD-317):

1850	Huntington, Gurdon	NY	Niagara Co.	Somerset	p. 349
1850	Huntington, Gurdon, Jr.	NY	Niagara Co.	Somerset	p. 349

Living eight doors down from son, Joshua HUNTINGTON. 

7b.  Family Quest Archives:  New York Federal Census 1850: Niagara County (part).  Heritage Quest CD M432-561:  Somerset, Niagara Co., NY, p. 349A, enumerated 9 Jul 1850 (extracted by Diana Gale Matthiesen):

60	60	Gurdon Huntington	66	M	Farmer	8000	Conn
		Polly      "	60	F			VT
		George     "	19	M	F		NY
		Morris     "	28	M	Sailor		"
60	61	Gurdon     "   Jr	25	M	F		"
		Sally      "	24	M (sic)			"
		Frances    "	4	F
		Henry      "	1	M
		Abagail    "	18	F
		Charles Bloomer	16	M	F		"

There's not a lot of logic to how this record is organized.  Certainly, Gurdon is their son and, presumably, George and Morris are also their children.  Abigail's position in the record indicates she is not their daughter, and her absence from the household in 1840 strengthens that conclusion.  Sally would appear to be Gurdon Jr.'s wife, and Frances and Henry their children.  Charles BLOOMER is likely a hired hand or boarder, though he could be kin.  "F" presumably means "farmer."  The cells were blank for the birthplaces of Frances, Henry, and Abigail.

8.  1790-1870 Census Index (online at Ancestry.com):

1860	HUNTINGTON	GURDON	NY	Niagara Co.	Somerset	p. 410
1860	HUNTINGTON	GURDON	NY	Niagara Co.	Somerset	p. 441

9.  Anon.  1915.  The Huntington Family in America: a Genealogical Memoir of the Known Descendants of Simon Huntington from 1633 to 1915.  Huntington Family Assn., Hartford, CT (online at GenealogyLibrary.com).  See full excerpt.  On p. 159:

GURDON HUNTINGTON, left Conn. with a very small amount of money in 1802 and worked his way into what was then the Western wilderness as far as Batavia, N.Y.  He had a family and acquired considerable wealth and influence.  He lived at one time in Rochester, N.Y. CHILD.   1.  GURDON.

10.  Daniel S. Durrie  1864.  A Genealogical History of the Holt Family in the United States: more particularly, Descendants of Nicholas Holt of Newbury and Andover, Mass., 1634-1644.  Munsell, Albany.

p. 136

1. DANIEL7 P. (3327) b. Brandon, Vt.; m. Nov. 24, 1824, Sarah, daughter of Gurdon Huntington of Batavia, N.Y.; removed to Somerset, Niagara county, N.Y...

11.  NARA.  Index to the Compiled Military Service Records for the Volunteer Soldiers Who Served During the War of 1812, M603, 234 Rolls. National Archives and Records Administration, Washington DC (digitized by Direct Data Capture, Provo, UT; online at Ancestry.com; missing columns were blank):

Surname	Given Name	Company	Rank- Induction	Rank- Discharge	Roll- Box	Roll- Exct
Huntington	Gurdon	Cap. Ellicott's Co., Art'y, New York Mil.	Private	Private	106	602

This could be our subject, but there were two Gurdon HUNTINGTON's the right age in NY at the time, so it could be the other one.