As for location, the history of the 19th Century political geography of Germany is exceedingly complex, so birthplace locations in the U.S. census may not correspond to today's names.  For example, Bavaria was for a time in control of parts of southern Germany that are now outside Bavaria.  Also, the ethnic German enclave of Alsace-Lorraine was alternately under German or French rule during the 19th century, creating an apparent inconsistency in birthplace for the many STRAUBs from that region.  In fact, when a STRAUB alternates between France and Germany as a birthplace, it's quite likely they're from Alsace-Lorraine. 

I am tentatively treating these census records as applying to the same family, but I may be incorrect in doing so, because it certainly is a stretch.  On the flip side, if these records don't pertain to one family, where are these other families in other census years?  I can't find them anywhere else, and it would be an amazing coincidence that the only STRAUB families in Madison should be so similar.  In any case, we do know from a primary document that George & Margaret (WITGRAVER) STRAUB are, for certain, the parents of Henry STRAUB, and thus, presumably, his siblings.  In other words, even if we reject the 1870 and 1880 census records and consider our subject "not found" in those years, we can still connect them as shown below. 

1.  Marriage Record:

2.  Indiana Births and Christenings, 1773-1933 (online at FamilySearch.org):

Name	Hermann Strub	Georg Strup	Georg Strupp
Gender	Male	Male	Male
Event Type	Christening	Christening	Christening
Event Date	15 Jul 1849	25 Dec 1853	25 Dec 1853
Event Place	St Johns United Church of Christ Madison, Jefferson, Indiana
Father's Name	Georg Strub	Georg Strup	Otiger Strupp
Mother's Name	Margarethe Strub
GS Film Number	1533450	1533450	1533450

Are these our subjects?  With a child baptized in 1849 and in 1853 in Madison, surely this couple should have been found in the 1850 census of Jefferson Co., IN.  There is no other George & Margaret STRAUB/etc. in Madison, so most likely these are our subjects.  The two readings for Georg imply the original record was hard to read, so the transcriber made two entries, though how "Georg" could also be "Otiger" is hard to fathom.  It would be worth tracking down the microfilm to clear this up. 

3.  1850 U.S. Census Every-Name-Index/Images (online at Ancestry.com):  can't find, and I really looked.

4.  1860 U.S. Census Every-Name-Index/Images (online at Ancestry.com, Image #126 of 326):  City of Madison (Ward 3), Jefferson Co., IN, Roll M653_270, p. 508, PN 211, 1567/1567, enumerated 28 Jul 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):¤•

George Strop	43	M		Laborer	935	300	France
Margaret  "	42	F					Bavaria
Catharine "	10	F					Ind
George    "	9	M					do
Henry     "	7	M					do

4.  1870 Census Every-Name-Index/Images (online at Ancestry.com, Image #148 of 390):  Madison P.O., City of Madison, Jefferson Co., IN, Roll M593_328, p. 323B, PN 26, 189/207, enumerated 6 Jun 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):¤•

Straub George	50	M	W	Woodsawer	2900	500	Prussia
"   Susan	39	F	W	Keeping house			Darmstaat
"   Richard	20	M	W	Woodsawer			Indiana
"   Henry	15	M	W	goes to School			do
"   Anna	10	F	W	do			do
"   Cathrine	2	F	W				do

I hate to attribute so much to enumerator error, but this does seem to be our subject and his family.  Margaret is 52, not 39, and Catharine is 20, not 2.  "Susan" and "Richard" may be enumerator error, or they may be alternate given names for Margaret and George.  Keep in mind that enumerators did not fill out the census schedules in the field.  They took notes in the field, then later used their notes to fill in the schedules, which were usually kept in the county court house, with all the error inherent in that transfer.  I would have suspected George was remarried to a younger woman, but we know Margaret is living, and they do appear to be together in 1880.  Another interpretation is that Margaret is estranged and Susan is simply living with George, making little Cathrine her daughter.

5a.  1880 U.S. Census Every-Name-Index/Images (online at Ancestry.com, Image #32 of 35):  Walnut [Street], Madison, Jefferson Co., IN, Roll 287, p. 133D, PN 32, SD 2, ED 123, enumerated 9 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	10	13	24	25	26
*	302	348	Schwab George	W	M	64		/	Laborer	Germany	Germany	Germany
			______ Magaret	W	F	62	Wife	/	Keeping house	Germany	Germany	Germany
*Walnut

I know it's a stretch from Schwab to Straub, but we know George was living on Walnut Street when he died in 1881 (as was Margaret when she died in 1900), and everything else jibes.  I do not find a George "Schwab" born this early anywhere in Indiana in the 1850, 1860, and 1870 censuses.

5b.  1880 U.S. Census Every-Name-Index/Images (online at Ancestry.com, Image #8 of 30):  North Side of High Street, City of Madison (Ward 1), Jefferson Co., IN, Roll 287, p. 106D, PN 8, Sd 2, ED 122, enumerated 2 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

73

73

Steffen Adam

W

M

30

/

Barber

Indiana

Germany

Germany

_______ Kate

W

F

27

Wife

/

Keeping House

"

"

"

_______ Peter

W

M

5

Son

/

"

Ind

Ind

_______ George

W

M

3

Son

/

"

"

"

Straub Annie

W

F

21

Sister

/

Boarder

Ohio

France

Bavaria

If Kate (STRAUB) STEFFEN and Annie are sisters, which they do appear to be, their parents had to be born in the same place.

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

7.  1900 U.S. Census Every-Name-Index/Images (online at Ancestry.com):  Margaret died in April, before the census was enumerated on June 1st.

8.  Find-a-Grave: Entries (online at findagrave.com):

Name	George Straub	Margaret Witgraver Straub
Birth	1817, Germany	1814, Germany
Death	Jan. 17, 1881 Madison, Jefferson Co., IN	Apr. 21, 1900 Madison, Jefferson Co., IN
Note	suicide by hanging "in the stable in the rear of his residence on Walnut street," due to alcohol intoxication	She died "at her home on North Walnut street."
Burial	Springdale Cemetery Madison, Jefferson Co., IN
Memorial #	101601096	105150296

.  LDS.  Family Search:  Pedigree Resouce File (online at familysearch.org):  not found.

.  Public Member Trees (online at Ancestry.com):  not found.

.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com):  not found.