This person has some good info on Daniel O'neil and may be able to help you:
http://boards.ancestry.com/surnames.oneil/684/mb.ashxO'Neil family of Rice County Minnesota
http://boards.rootsweb.com/surnames.carney/1701/mb.ashxBridget CARNEY and Daniel O'NEIL in RICE COUNTY, Minnesota
You can register for free on Ancestry.com to post your query as a reply to either message, and that person would be automatically notified of your post.
Based on the given info, I found an Illinois marriage record here:
http://www.ilsos.gov/isavital/marriagesrch.jspGroom Bride Date Volume Page Lic No. County
ONEIL, DANIEL O CARNEY, BRIGIT 1856-02-03 00A 0097 00001474 ROCK ISLAND
This link gives info on how to obtain a copy of the marriage certificate:
http://cyberdriveillinois.com/departments/archives/databases/marriage.htmlThe 1860 census was the first after they married. It looks like Daniel may have had a younger brother Michael living with them.
1860 United States Federal Census about Daniel Oneal
Name: Daniel Oneal
Age in 1860: 27
Birth Year: abt 1833
Birthplace: Ireland
Home in 1860: Greenvale, Dakota County, Minnesota
Gender: Male
Post Office: West St Paul
Household Members:
Name Age
Daniel Oneal 27
Bridgett Oneal 24, b. Ireland
Micheal Oneal 17, b. Ireland
Bridgett Oneal 1, b. Minnesota
1870 United States Federal Census about Daniel Oniel
Name: Daniel Oniel
Age in 1870: 38
Birth Year: abt 1832
Birthplace: Ireland
Home in 1870: Deerfield, Steele, Minnesota
Race: White
Gender: Male
Post Office: Deerfield
Household Members:
Name Age
Daniel Oniel 38
Bridget Oniel 38
Michael Oniel 9
Timothy Oniel 7
John Oniel 5
Daniel jr. Oniel 3
Edward Oniel 1
Thomas Oniel 4/12
Bridget Oniel 10
1880 United States Federal Census about Daniel Oneal
Name: Daniel Oneal
Age: 48
Birth Year: abt 1832
Birthplace: Ireland
Home in 1880: Deerfield, Steele County, Minnesota
Marital Status: Married
Spouse's Name: Brigart Oneal
Father's Birthplace: Ireland
Mother's Birthplace: Ireland
Occupation: Farmer
Household Members:
Name Age
Daniel Oneal 48
Brigart Oneal 47
Mickel Oneal 19
Timothy Oneal 16
John Oneal 15
Daniel Oneal 14
Edmond Oneal 12
Thomas Oneal 10
Sarah Oneal 9
Morris Oneal 4
All children b. Minnesota
To see Daniel's gravestone enter Daniel's name and death year here:
http://findagrave.com/cgi-bin/fg.cgiSee here for some info on the Church of the Immaculate Conception:
http://www.southernminn.com/faribault_daily_news/archives/article_7abe67e0-4cff-5c8a-bfde-1f5b1453226d.htmlFaribault's Catholic separation
You might try to contact the James Mathewson mentioned to see if he has any info on Daniel O'neil, or could advise you in your search. Contact him, maybe, through someone at the newspaper:
http://www.southernminn.com/faribault_daily_news/site/contact.htmlThis also might be him, with an address:
http://www.peoplebyname.com/people/Mathewson/James/Faribault/MN