[Fiji Hill]

So I can't tell you when the last sign came down, but it wouldn't surprise me if it persisted until WW2 when military service erased many former ethnic barriers. Last I checked, WW2 was in the middle of the 20th century.

"No Irish need apply" is usually associated with the mid-nineteenth century, and academics dispute as to how widespread the sentiment was.

[Albion Wilde]

If it makes you happy to fight about it, whatever.