1.  Marriage Record:

2.  1860 Census Every-Name-Index/Images (online at Ancestry.com):  can't find Dennis.  Louisa is living with her first husband in Alameda.

3.  1870 Census Every-Name-Index/Images (online at Ancestry.com, Image #33-34 of 39):  Alameda P.O., Alameda, Alameda Co., CA, Roll M593_68, pp. 17A-17B, PN 33-34, 246/233, enumerated 10 Aug 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):¤•

Straub D U	45	M	W	House Carpenter			Prusia
"   Lousia	36	F	W	Keeps house	4000	500	"
[Louisa's children from her prior marriage]
[next page]
Lacawasha L	80	F	W	at home			Prusia

4.  1880 Census Every-Name-Index/Images (online at Ancestry.com, Image #14 of 46):  Alameda, Alameda Co., CA, Roll T9_62, p. 640B, PN 14, SD 2, ED 30, enumerated 3 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
137	140	Straub Dennis	W	M	59		/	Carpenter & Builder	Wurtemburg	Wurtemburg	Wurtemburg
		______ Louisa	W	F	45	Wife	/	Keeping House	Wurtemburg	Wurtemburg	Wurtemburg
		[Louisa's children from her prior marriage]
		Zadiq Peter	W	M	73		/	Solicitor & Ins Co	Germany	Germany	Germany
		_____ Losetta	W	F	65	Wife	/	Keeping House	Germany	Germany	Germany