The Irish-Italian connection/tradition originates with the two cultures merging in New Orleans after WWII.
The Irish
In terms of numbers and influence, the Irish were first in New Orleans. O’Reilly is an outlier on this; the Irish influence begins in the 1820s. That first wave of Irish immigrants provided the manpower to build the New Basin Canal.
Crescent City Living’s video on the Irish Channel, produced by Crista Rock, with commentary from NOLA History Guy.
The Irish in New Orleans
Love New Orleans? Thank an Irishman
The story of St. Alphonsus and St. Mary’s Assumption churches
The Irish Cemeteries
Ten Contributions the Irish Made to New Orleans
These are articles about the Irish I’ve written over the years. This podcast doesn’t go into a ton of detail, since its focus is how all these folks ended up in the same parade.