1.  Marriage Record:

2.  1880 Census Every-Name-Index/Images (online at Ancestry.com, Image #10 of 10):  Lake Town[ship], Polk Co., WI, Roll T9_1442, p. 289B, PN 18, SD 3, ED 199, enumerates 23/24 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

21

24

25

26

137

147

Jorgeson Iver

W

M

39

/

Farmer

DK

DK

DK

________ Serine

W

F

35

Wife

/

Housekeeper

DK

DK

DK

________ Anna

W

F

7

Dau

/

At home

/

WI

DK

DK

________ Bernhardt

W

M

5

Son

/

At home

/

WI

DK

DK

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

4.  1900 Census Every-Name-Index/Images (online at Ancestry.com, Image #7 of 17):  Laketown Town[ship], Polk Co., WI, Roll T623_1811, p. 150A, SN 4, SD 9, ED 134, enumerated 7/8 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	16	17	18	19	22	23	24	25	26	27	28
60	60	Jergensen Iver	Head	W	M	Feb 1841	59	M	27			DK	DK	DK	1872	28	Na	Farmer	Y	Y	Y	O	F	F	60
		_________ Sorine	Wife	W	F	Nov 1844	55	M	27	3	2	DK	DK	DK	1872	28		Keeping House	Y	Y	N
		_________ Anna	Dau	W	F	Sep 1873	26	S				WI	DK	DK					Y	Y	Y
		_________ Berhardt	Son	W	M	Jun 1875	24	S				WI	DK	DK				Farmer	Y	Y	Y	T

5.  1910 Census Every-Name-Index/Images (online at Ancestry.com, Image #7 of 17):  Laketown Twp., Polk Co., WI, Roll T624_1733, p. 143A, SN 4A, SD 10, ED 166, enumerated 28 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	12	13	14	17	18	19	20	23	24	25	26	27	28	29
78	78	Jeorgensen Bern	Head	M	W	34	M1	6	WI	DK Dan	DK Dan	Eng	Farmer	Farming	Emp	Y	Y		O	F	F	65
		[Bernhardt's wife and children]
		__________ Annie J	Boarder	F	W	35	S		WI	DK Dan	DK Dan	Eng	none			Y	Y	Y

In addition to difficult handwriting, the record has faded away in places.  I wouldn't trust the middle initials.

6.  1920 Census Every-Name-Index/Images (online at Ancestry.com, Image #16 of 22 — indexed "Bernhard Jorgenson"):  Laketown Twp., Polk Co., WI, Roll T625_2010, p. 250B, SN 8B, SD 10, ED 158, enumerated 31 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).
2	3	4	5	6	7	8	9	10	11	12	17	18	19	21	22	23	24	25	26	27	28	29
Fm	164	165	Jorgenson Bernhardt	Head	O	F	M	W	44	M	Y	Y	WI	DK	Dan	DK	Dan	Y	Farmer	general farm	Em	164
			[Bernhardt's wife and children]
			_________ Annie	Sister			F	W	45	S	Y	Y	WI	DK	Dan	DK	Dan	Y	none

7.  1930 Census Every-Name-Index/Images (online at Ancestry.com, Image #9 of 23 — indexed "Bean Jorgenson"):  Laketown Twp., Polk Co., WI, Roll 2605, p. 177B, SN 4B, ED 48-22, SD 1, enumerated 17 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	9	10	11	12	13	14	15	16	17	18	19	20	24	25	26	27	28	30	32
79	81	Jorgenson Bern	Head	O	R	Y	M	W	54	M	28	N	Y	WI	DK	DK	Y	Farmer	dairy farm	O	Y	N	72
		[Bernhardt's wife and children]
		_________ Anna	Sister				F	W	55	S		N	Y	WI	DK	DK	Y	House work	farm home	NP	Y

8.  Haustrup Cemetery, Laketown, Polk Co., WI (online in the archives of the Polk County, WIGenWeb site; submitted by Christine Jackson):

Jorgenson, Iver	Feb 24, 1841	Jul 04, 1905
Jorgenson, Sorine Frederica	Nov 30, 1844	Apr 07, 1909
Jorgenson, Anna	Sep 22, 1873	Nov 08, 1946
Jorgenson, Frederick K.	1875	1879

There are 14 JORGENSONs in the cemetery, and they can all be tied to this family, either as children or grandchildren (or their spouses).  Surely Frederick is their son, and if Frederick was born in 1875, then he has to have been a twin of Bernhardt's.

9.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).

10.  LDS.  Family Search: Internet Genealogy Service: Pedigree Resource File (index to CDs, online at FamilySearch.org).

11.  Email from descendant.