1a.  LDS.  Family Search: Internet Genealogy Service: Pedigree Resource File (index to CDs, online at FamilySearch.org).

CD#47 Sylvester Benjamin HOPKINS Birth: 1818, New York; Death: 12 Jan 1883, Pomeroy, Garfield, WA Father: Samuel HOPKINS; Mother: Naoma Marriage: 21 Mar 1841, Yankee Springs, Barry, Mich Spouse: Marilla J GROVES Birth: 1826, New York; Death: 1863/70, Iowa Source: patron submission

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

Sylvester Benjamin HOPKINS Death: 12 Jan 1883 Spouse: Marilla J GROVES Birth: 1826 Marriage: 21 Mar 1841, Yankee Springs, Barry, Michigan Source: patron submission

S. B. HOPKINS Marriage: 10 Dec 1868, Pottawattamie, Iowa Spouse: Laura A. HOPKINS Source: patron submission

2.  1850 Census Index/Images (online at Ancestry.com; Image #2 of 7):  Carlton Twp., Barry Co., MI, p. 113B, 725/744, enumerated 12 Sep 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):

Sylvester B Hoptkins	34	M		Carpenter		N York
Marilla        "	24	F				"
Miles          "	4	M				Mich
George         "	2	M				"

Marilla was born in New York, but three other censuses show Sylvester born in Ohio.

3a.  1860 Census Index/Images (online at Genealogy.com, Image #3 of 14):  Crescent City P.O., Crescent Twp., Pottawattamie Co., IA, Roll 338 (Book 1), p. 383, PN 81, 600/539, enumerated 30 Jun 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):

Sylvester B Hopkins	33	M		Carpenter		200	Ohio
Morrella J     "	33	F		House wife			New York
Marsha A       "	15	F		House work			Michigan
Miles          "	14	M					"
George         "	12	M					"
Laura? H       "	8	F					"
Charles B      "	6	M					Illinois
Walter H       "	11/12	M					Iowa

Marsha and Laura are also enumerated with Sylvester's married sister, Marcia/Marsha A. (HOPKINS) FOLSOM (see next Source), but there, the teenage Marsha is surnamed FOLSOM.  As the younger Marsha is living with the FOLSOMs and is surnamed FOLSOM in the 1850 census, I'm inclined to believe she is Marsha (HOPKINS) FOLSOM's daughter.  Laura's position is more ambiguous, but I'm going to assume she's Sylvester's daughter.

3b.  1860 Census Index/Images (online at Genealogy.com, Image #41 of 55):  Council Bluffs P.O., Council Bluffs City (Ward 4), Pottawattamie Co., IA, Roll 338 (Book 1), p. 343, PN 41, 314/276, enumerated 13 Jun 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):

Jeremiah Folsom	43	M		Trader	30000	?000	Massachusetts
Marcia A    "	44	F		House wife			Connecticut
Marcia A    "	16	F		At School			Michigan
Laura H Hopkins	8	F					Michigan
Harriet E Springtten?	18	F		Servant			Pennsylvania
Henry ?????	55	M		Farmer			Massachusetts
Samuel Folsom	24	M		Merchant Clk	7000		"

Marcia/Marsha A. (HOPKINS) FOLSOM is Sylvester's sister.

4.  1870 Census Index/Images (online at Genealogy.com, Image #1 of 7):  Cuming City P.O., Silver Creek, Burt Co., NE, p. 35A, PN 1, 1/1, enumerated 27 Jun 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):

Hopkins Silvester	53	M	W	House Carpenter	1000	1400	Ohio
_______ Laura A	48	F	W	Keeping house			New York
_______ Mary	18	F	W	Without occupation			Mishagon
_______ Charles	16	M	W	Working on farm			Illinois
_______ Frank	15	M	W	at home			Iowa
_______ Elmer	7	M	W	at home			Iowa

Mary and Frank appear to be Laura's children from her prior marriage.  I checked every HOPKINS household indexed in Iowa and in Michigan in 1860 and did not find Laura, Mary, or Frank.

5.  1880 Census (indexed at FamilySearch.org; page image online at Ancestry.com, Image #9 of 36):  District No. 3, Columbia Co., Washington Territory, Roll , p. 150A, PN 9, SD _, ED 53, enumerated 5 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
84	90	Hopkins S B	W	M	62			/	Farmer	OH	CT	CT
		_______ Laura A	W	F	57	Wife		/	Keeping house	NY	NY	VT
		_______ Elmer E	W	M	17	Son	/		Works on farm	IA	OH	NY

6.  1890 Census:  the 1890 Census Population Schedules were destroyed.

7.  U.S. Dept. of the Interior, Bureau of Land Management. The Official Land Patent Records Office.

Date	Cert. No.	Land Office	Patented By	Acres	Aliquot Sec.Twp.Rng	Meridian	State	County*
17 Jun 1850	7153	Ionia	Sylvester B Hopkins of Barry County, Michigan	40	NE¼ NW¼ S19.T4N.R8W	Michigan-Toledo Strip	MI	Barry
*The county is not given on the original certificate, which describes the location of the land solely in terms of Aliquot, Section, Township, and Range.  The county names must have been added to the database at some later time, probably when the certificate data were computerized.