Edits with documentation appreciated...
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Married twice.... as shown on LDS Family Chart
1] Ellen Brosnahan on 21 Jan 1889 in St. Paul, Ramsey, Minnesota
https://familysearch.org/ark:/61903/1:1:Q2Z5-3GYJ
She has her FAG created....and buried in New Rockford, Eddy County, North Dakota
2] Elizabeth MNU of Minnesota m. abt 1921
https://www.familysearch.org/tree/pedigree/landscape/LTC7-BCY
No 1900 Census on him but 1910 Census shows he and his family in North Dakota...
Census, 1910
Name: John Casey
Event Type: Census
Event Date: 1910
•
Event Place: Munster, Eddy, North Dakota, United States
•
Event Place (Original): Munster, North Dakota
Sex: Male
Age: 50
Marital Status: Married
Race: White
Race (Original): White
Birth Year (Estimated): 1860
Birthplace: Ireland
•
Immigration Year: 1884
Father's Birthplace: Ireland
Mother's Birthplace: Ireland
Relationship to Head of Household: Head
Relationship to Head of Household (Original): Head
Sheet Letter: A
Sheet Number: 6
Household Role Sex Age Birthplace
John Casey Head Male 50 Ireland
Ellena Casey Wife Female 47 Ireland
Joseph Casey Son Male 17 Minnesota
Patrick Casey Son Male 13 Minnesota
Daniel Casey Son Male 11 Minnesota
Thomas Casey Son Male 9 Minnesota
Eileen Casey Daughter Female 7 North Dakota
Kathleen Casey Daughter Female 5 North Dakota
.......
No 1900 Census on him but 1910 Census shows he and his family in North Dakota...

United States Census, 1910
Name: John Casey
Event Type: Census
Event Date: 1910
•
Event Place: Munster, Eddy, North Dakota, United States
•
Event Place (Original): Munster, , North Dakota
Sex: Male
Age: 50
Marital Status: Married
Race: White
Race (Original): White
Birth Year (Estimated): 1860
Birthplace: Ireland
•
Immigration Year: 1884
Father's Birthplace: Ireland
Mother's Birthplace: Ireland
Relationship to Head of Household: Head
Relationship to Head of Household (Original): Head
Sheet Letter: A
Sheet Number: 6

Household Role Sex Age Birthplace
John Casey Head Male 50 Ireland
Ellena Casey Wife Female 47 Ireland
Joseph Casey Son Male 17 Minnesota
Patrick Casey Son Male 13 Minnesota
Daniel Casey Son Male 11 Minnesota
Thomas Casey Son Male 9 Minnesota
Eileen Casey Daughter Female 7 North Dakota
Kathleen Casey Daughter Female 5 North Dakota

https://www.familysearch.org/tree/person/sources/LTC7-BCY

Name: John Casey
Event Type: Death
Event Date: 5 Nov 1942
Event Place: St. Paul, Ramsey, Minnesota, United States
Event Place (Original): St Paul, Ramsey, Minnesota
Sex: Male
Age: 82
Birth Date: 1860
Birthplace: Ireland
Father's Name: Martin Casey
Mother's Name: Mary McCarthy
Spouse's Name: Elizabeth Casey
Certificate Number: 25836
......