1.  Marriage Record:

2.  Census Index:  U.S. Selected Counties, 1840 (Broderbund CD-316):  can't find. 

3.  Census Index:  U.S. Selected Counties, 1850 (Broderbund CD-317):  can't find, unless they are the couple in Cayuga County whose ages are off.  As boarders, that kind of mistake is possible. 

4.  1860 Census Images (online at Ancestry.com; Image #16+17 of 71 — both Augustus and Margaret are indexed):  Sheldon Centre P.O., Sheldon, Wyoming Co., NY, pp. 192B-193A, PN 52-53, 386/112, enumerated 19 Jul 1860 (extracted by Diana Gale Matthiesen):¤•

Augustus Straub	52	M		Farmer	1200	500	Bavaria
[next page]
Margarit Straub	52	F					Bavaria
Lana Weidmayer	54	F		domestic			"
Nicholas Howsour	25	M					Switzerland

The only other STRAUB/STROUP/etc. household in the county was our subject's brother, Nicholas STRAUB. 

5.  1870 Census Index/Images (online at Genealogy.com; Image #35 of 58):  Varysburgh P.O., Town of Sheldon, Wyoming Co., NY, Roll 1119 (Book 1), p. 317A, PN 35, 277/287, enumerated 17 Jun 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):¤•

Straub Barney	63	M	W	Farmer	1000	400	Bavaria
"   Margaret	58	F	W	Keeping house			"

Margaret appears to be fibbing about her age; either that, or her age in the 1850 census is wrong.  Listed next to brother, Nicholas STRAUB. 

6.  1880 Census Images (online at Ancestry.com; Image #40 of 48):  Sheldon, Wyoming Co., NY, p. 278B, PN 38, SD __, ED 210, enumerated 19 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	11	13	24	25	26
387	399	Straub Barnard	W	M	72	/	Retired Farmer	Bavaria	Bavaria	Bavaria

Listed four households from his brother, Nicholas STRAUB. 

8.  Mea culpa.  I lost the source.

429 - Marie Margaretha, w/o A. Bernard, d. 1870 age 68 430 - A. Bernard, d. 1888 age 79