1.  Marriage Record:

2.  1880 Census (indexed at FamilySearch.org; page image online at Ancestry.com, Image #41 of 70):  451 H Street NW, Washington, Washington Co., District of Columbia, Roll 123 (Book 1), p. 126C, PN 39, SD 17, ED 49, 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

7

8

9

10

13

14

24

25

26

321

431

Straub Rudolph

W

M

33

/

Plasterer

10

Dist of Col

Prussia

Prussia

______ Anna T?/Y?

W

F

33

Wife

/

Keeping House

Pennsylvania

Ireland

Ireland

______ Ignatus

W

M

8

Son

/

Dist of Col

D.C.

Penn

______ Rudolph

W

M

6

Son

/

Dist of Col

D.C.

Penn

______ Bernard A

W

M

3

Son

/

Dist of Col

D.C.

Penn

______ Margaret

W

F

8/12

Sept

Dau

/

Dist of Col

D.C.

Penn

Bork? Eugene M

W

F

19

Neice

/

Servant

Pennsylvania

Penn

Penn

The LDS read Anna's middle initial as "T."

3.  1890 Census:  the 1890 Census Population Schedules were destroyed.

4.  1900 Census Index/Images (online at Genealogy.com, Image #107 of 482 — indexed "Straut"):  1845 Twelveth Street, Washington City, District of Columbia, Roll 160 (Book 2), p. 56B, SN 5B, SD 1, ED 50, 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

10

11

12

13

14

15

19

20

22

23

24

25

27

*

1845

81

93

Straub Rudolph

Head

W

M

Mch 1847

53

M

25

Dist of Col

Germany

Germany

Plasterer

5

Y

Y

Y

R

H

______ Anna

Wife

W

F

Oct 1854

45

M

25

4

4

Pennsylvania

Ireland

Ireland

Y

Y

Y

______ Rudolph Jr

Son

W

M

Dec 1876

23

S

Dist of Col

Dist of Col

Pennsylvania

Horseshoer

6

Y

Y

Y

______ Margaret

Dau

W

F

Jan 1872

18

S

Dist of Col

Dist of Col

Pennsylvania

Plate Printer's Helper (Gov)

0

Y

Y

Y

*Twelth Street

The only one whose age and birthyear appear to be correct is Rudolph Sr's.  Anna should be the same age as Rudolph, so my guess is she's the informant who has lowered her children's ages and made her marriage more recent to support her fib about her own age.  (Don't be skeptical, my grandmother used to lie about her children's ages to support her lie about her own age.)  Margaret was born Sep 1879, not Jan 1872 — which is a double mistake because if Margaret were truly 18, she'd have been born in 1882, not 1872.  Rudolph Jr. should be 26, not 23.

5.  Anon.  1890.  Washington, D.C., City Directory, 1890.  R.L. Polk Co., Washington, DC (online at Ancestry.com):

1890/1891 Rudolph Straub, plasterer, 1216 U Northwest, Washington, DC