1.  Marriage Record:

2.  1900 Census Every-Name-Index/Images (online at Ancestry.com):  can't find.

3.  1910 Census Index/Images (online at Ancestry.com, Image #4 of 28):  335 Graham Street, Pittsburgh (Ward 8), Allegheny Co., PA, Roll 1302 (Part 1), p. 2B, SN 2B, SD 23, ED 380, enumerated 16 Apr 1910, official enumeration date 15 Apr 1910 (extracted by Diana Gale Matthiesen):¤•

1910:  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	10	11	12	13	14	15	17	18	19	20	21	22	23	24	25	26	27	28
*	335	33	33	Straub David K	Head	M	W	40	M1	10			PA	PA	PA		Eng	Manufacturer	Brewery	Emp			Y	Y		O	M	H
				______ Mary	Wife	F	W	28	M1	10	3	1	IN	IN	PA		Eng	None					Y	Y
				______ Carl	Son	M	W	8	S				PA	PA	IN			None							Y
				Casphus? Dora	Servant	F	W	20	S				Hung. Magyar	Hung. Magyar	Hung. Magyar	1907	Eng	Servant	Private family	W	N	0	Y	Y	N
*Graham Street

This page image was very difficult to read at Ancestry.com and impossible to read at Genealogy.com.  My extraction may not be entirely accurate.

4.  1920 Census Index/Images (online at Ancestry.com, Image #4 of 24):  5216 Liberty(?) Avenue, Pittsburgh City (Ward 8), Allegheny Co., PA, Roll T625_1517, p. 224B, SN 2B, SD 24, ED 446, enumerated 3/4 Jan 1920, official enumeration date 1 Jan 1920 (extracted by Diana Gale Matthiesen):¤•

1920:  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

9

10

11

12

16

17

18

19

21

23

25

26

27

28

*

5216

38

43

Straub Detmar K

Head

R

M

W

45

M

Y

Y

PA

PA

PA

Y

Superintndent

Brewing co.

Em

______ Anna M

Wife

F

W

40

M

Y

Y

PA

OH

PA

Y

None

______ Karl

Son

M

W

16

S

Y

Y

Y

PA

PA

PA

Y

None

*Liberty? Ave

I can't actually read the street name, but Dietmar appears to be living in his parents' house at 5216 Liberty Avenue, where his parents were living in the 1900 and 1910 censuses.  Dietmar's father has died since the 1910 census, and his mother is now living with his brother, Herman A. STRAUB, Jr. 

5.  1930 Census Index/Images (online at Ancestry.com, Image #3 of 10):  Independence Twp., Beaver Co., PA, Roll 1996, p. 241A, SN 2A, ED 4-65, SD 7, enumerated 7 Apr 1930, official enumeration date 1 Apr 1930 (extracted by Diana Gale Matthiesen):¤•

1930:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).
3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	24	25	26	27	28	30	32
35	38	Straub Detmar K	Head	O	$3000	R	Y	M	W	55	M	26	N	Y	PA	PA	PA	Y	Farmer	General Farming	O	Y	N	19
		______ Mary B	Wife					F	W	50	M	21	N	Y	PA	OH	PA	Y	None

Listed next to Detmar's brother, Herman A. STRAUB, Jr. 

6.  Allegheny Cemetery, Pittsburgh, Pennsylvania: STRAUB - ANSHUTZ Plots (courtesy of Amy Denecke).

Detmar K. Straub Oct. 6, 1874 - Dec. 17, 1943

Mrs. Mary Beeson Straub 10-1-58

7.  Messages posted to the Straub Family Genealogy Forum (online at GenForum.com)