1.  Marriage Record:

2.  1860 Census Images (online at Ancestry.com; Image #26 of 30):  Pleasant Gap P.O., Benner Twp., Centre Co., PA, p. 342, PN 250, 1751/1807, enumerated 16 Aug 1860 (extracted by Diana Gale Matthiesen):

William Straub	32	M		Carpenter	500	300	Penna
Nancy     "	31	F					"
Edmund M. "	10/12	M					"

3.  1870 Census Images (online at Ancestry.com; Image #13 of 41):  Bellefonte P.O., Spring Twp., Centre Co., PA, p. 725A, PN 13, 94/91, enumerated 21 Jul 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):

Straub William	42	M	W	Carpenter	2800	500	Penna
______ Nancy	42	F	W	Keeping House			Penna
______ Edmund	10	M	W				Penna
______ Elmer E	8	M	W				Penna
______ Emma	4	F	W				Penna

4.  1880 United States Census and National Index (LDS Family History Resource File: CD-ROM Library):

Census Place: Spring, Centre, Pennsylvania
Source: FHL Film 1255112; NARA Film T9-1112; Pg 204C
	Relation	Sex	Marr	Race	Age	Birthplace	Occupation	Fa	Mo
William STRAUB	Self	M	M	W	51	PA	Carpenter	PA	PA
Nancy STRAUB	Wife	F	M	W	51	PA	Keeping House	PA	PA
Edmund W. STRAUB	Son	M	S	W	20	PA	Apprentice Machinist	PA	PA
Ellsworth STRAUB	Son	M	S	W	18	PA	Apprentice To Shoemaker	PA	PA
Emma B. STRAUB	Dau	F	S	W	14	PA		PA	PA

I checked the page image online at Ancestry.com, and Edmund's middle initial is definitely written "W."  The only other STRAUB/STROUB/STROUP in Centre Co. is William's brother, Levi STRAUB. 

5.  Anon.  Friday, 19 Jul 1901.  "Obituaries." The Democratic Watchman, Bellefonte, Centre Co., PA (transcript courtesy of John S. Chillings, via Matthew D. Friend):

WILLIAM STRAUB, died on Thursday evening last of dropsy and heart trouble.  He was born in New Berlin, Union County, April 9, 1829, a son of George and Elizabeth Straub, and came to this County when only 17 years of age.  He first located at Pleasant Gap, but later came here, where for 30 years he was connected with the Jenkins and Lingle Foundry as a pattern maker.  His wife Nancy Ashton, daughter of James Ashton, of Centre Furnace, and to whom he was married on the 22 of Dec. 1854, died 4 years ago, but he is survived by their three children.  Emma Blanch, at home, and E. Milton, and Elmer E. Straub, both of this place.  He is also survived by the following brothers and sisters, Henry Straub, of Brookville; Levi, of Chicago; Edward, and Mrs. Isaac Miller of Bellefonte, and Mrs. Lydia Weaver, of Brush Valley. Interment in Union Cemetery.

6.  U.S. Geological Survey.  GNIS:  Geographic Names Information Service (online database).  There are three Union Cemeteries in Centre Co., PA, one in Bellefonte, one in Millheim, and one in unincorporated county area, between Bellefonte and Millheim.  Given that William's obituary was published in a Bellefonte newspaper, it's probably safe to assume William was buried in the Union Cemetery in Bellefonte.

7.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).  Mentions an article in the Pennsylvania Centre Democrat newspaper indicating our subjects lived in Bellefonte, Centre Co., PA.