O'Riley of Cavan County

My g-gg grandparents, John O'Riley (DOB Feb 13, 1818) and Anna Littlefield Cusack (DOB Dec 10, 1819) immigrated to Paoli, Dane County, Wisconsin, from County Cavan, Ireland, between 1830 and 1850 U.S. census.

I'm looking for information about how John and Anna got to Wisconsin from Cavan, Ireland.

Marriage record from Ireland or Certificates of Irish Births.

Searching for baptism records and marriage for John or Anna.

Children are:

Mary Ann O'Riley       (DOB Feb 22, 1850) in Montrose, Dane, Wisconsin.

Frank O'Riley              (DOB Mar 11, 1853) in Paoli, Dane, Wisconsin.

Joseph Dixon Riley     (DOB Feb 22, 1855) in Paoli, Dane, Wisconsin.

Margaret O'Riley        (DOB Apr       1858) in Paoli, Dane, Wisconsin

Catherine O'Riley       (DOB July      1860) in Montrose, Dane, Wisconsin

O’REILLY, O’RILEY, RIELLY, RILEY, O’RIELLY, CUSACK, (O'CISOGHE)