Don’t think the ape depictions ended with the Civil War.
And that is only in the US. The prejudice against the Irish continued much longer in GB.
The lot of the Irish in the US improved considerably after the Civil War; I’m sure the racism didn’t disappear completely. As for Britain (I never refer to it as “great”), I would expect nothing more from those who seized Ireland. They understood why Ireland wouldn’t black out in the Blitz decades later; when they told Ireland’s government the German pilots were navigating by the lights of Ireland I’m sure the Irish set bonfires every night from that point on.