1.  Marriage Record:

2.  1860 Census Images (online at Ancestry.com; Image #72 of 267 — indexed "Knoblack"):  Buffalo P.O., Buffalo City (Ward 5), Erie Co., NY, pp. 742B-743A, PN 72-73, 456/597, enumerated 27 Jun 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):

John Knoblack	39	M		Shoemaker	600	200	Hesse-Darmstadt
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Mary Knoblock	27	F					Mecklenburg
Charles Knoblock	3	M					New York
Henry Knoblock	1	M					"

It is very difficult to tell this enumerator's lowercase "a's" from his "o's."  The surnames could be read Knablack, Knablock, Knoblock, Knoblack.  Listed two households from Charles KNOBLOCH (æ 34, b. Hesse-Darmstadt), who is almost certainly John's brother. 

3.  1870 Census Images (online at Ancestry.com; Image #140 of 299):  Buffalo (Ward 6, Dist. 26), Erie Co., NY, p. 71A, PN 142, 794/138, enumerated 29 Jun 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):

Knoblack John	41	M	W	Saloon Keeper	8000	300	Hesse Darmstadt
________ Mary	37	F	W	Keeping House			Meklenburg
________ Charles	13	M	W				N York
________ Henry	11	M	W				"
________ Mary	8	F	W				"
________ John	6	M	W				"
________ Emelia	7/12	F	W				"	Nov
Knoblock Mary	19	F	W	domestic Servant			"

Charles KNOBLOCH is in Ward 5. 

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

Census Place: Buffalo, Erie, New York
Source: FHL Film #1254829; NARA Film #T9-0829; Pg 6D
	Relation	Sex	Marr	Race	Age	Birthplace	Occupation	Fa	Mo
John KNOBLACH	Self	M	S	W	16	NY	At Home	DARMSTADT	MECKLENBERG
Mary KNOBLACH	Mother	F	W	W	47	MECKLENBERG	Keeping house	MECKLENBERG	MECKLENBERG
Charles KNOBLACH	Brother	M	S	W	23	NY	At Home	DARMSTADT	MECKLENBERG
Henry KNOBLACH	Brother	M	S	W	21	NY	At Home	DARMSTADT	MECKLENBERG
Mary KNOBLACH	Sister	F	S	W	18	NY	At Home	DARMSTADT	MECKLENBERG
M. Emilie KNOBLACH	Sister	F	S	W	10	NY	At School	DARMSTADT	MECKLENBERG

5.  1890 Census:  the 1890 census population schedules were destroyed.

6.  1900 Census Index/Images (online at Genealogy.com):  49 Reed Street, Buffalo (Ward 14), Erie Co., NY, p. 242A, SN 6, SD 17, ED 106, enumerated 5 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	11	12	13	14	15	16	17	19	20	22	23	24	25	26	27
59	93	Knobloch Mary	Head	W	F	Jan 1833	67	W	6	4	Ger	Ger	Ger	1852	47			Y	Y	Y	O	F	H
		Schuster Mary	Servant	W	F	April 1883	17	S			NY	NY	NY			Servant	0	Y	Y	Y