Are Irish Catholics as concentrated in the Northeast as Italian Americans?

[King of Kensington]

Obviously Irish ancestry is more dispersed than Italian ancestry, but at least half of Americans of Irish ancestry are of Protestant background from the surveys I've seen (and few of the Protestants live in the Northeast).  But "Irish Americans" are basically Catholic, there's no real separate Irish Protestant identity separate from generic white Americans.  Are Catholic Irish Americans as concentrated in the Northeast as Italian Americans?

[King of Kensington]

My guess is no either.  Irish are two or three generations ahead of Italians in terms of the immigrant experience, plus they were already English speaking and moved faster into the British/Northwest European mainstream (and hence were more likely to convert to Protestantism).  Surnames like O'Toole and Flanagan don't stick out in say Iowa the way Esposito or Rossi do.

Of course from ancestry figures it's impossible to know whether one is Catholic or Protestant, or whether they're descended from Catholics who converted etc.

[King of Kensington]

Did some googling and found that 46% of Irish Catholics ca. 1980 lived in the Northeast (Italian Americans were 57% in the NE according to 1980 census).  Obviously the proportion for both has declined since.

[King of Kensington]

The only plurality Irish ancestry counties in the US are in the Northeast (the furthest west is Lackawanna, PA and the furthest south is Cape May, NJ), except for interesting isolated exceptions in Butte-Silver Bow, MT and Loving, TX, which are both pretty demographically exceptional counties for a variety of reasons, but tend to be more suburban/exurban/rural rather than urban, not a huge surprise given that Irish-Americans mostly arrived a couple of generations before Italian-Americans.

The biggest concentration is not surprisingly in the Boston area, the most "Irish" metro, particuarly the South Shore suburbs (aka the Irish Riviera). 

Philadelphia might be #2 in terms of the Irish feel - they're the largest ancestry group in the metro and some of the suburban counties are around 25% Irish ancestry. 

[King of Kensington]

Regional distribution:

Irish ancestry

Northeast  8,490,000  26%
Midwest  8,030,000  24%
South  10,600,000  32%
West  6,010,000  18%

Scotch-Irish ancestry

Northeast  361,000  12%
Midwest  508,000  17%
South  1,590,000  52%
West  601,000  20%

Only a small number of people identify as "Scotch-Irish" in the Census (many would presumably write "Irish" or just "American") but from what I've seen about half of Protestants of Irish ancestry live in the South so it's probably a fairly decent proxy measure for the "Protestant Irish" population.

[King of Kensington]

From the 1990s:

South:  Protestant 73%, Catholic 19%

Non-South:  Catholic 45%, Protestant 39%

Can't find anything beyond South/non-South but New England likely was as Catholic-dominated as South is Protestant-dominated.  

Though Massachusetts - the most Irish-Catholic state - has undergone a big shift to nonaffiliation since then.