Prisoners of war, as well as common criminals were shipped from the islands to colonies all over the world. They weren’t all Irish but some were.
From wiki https://en.wikipedia.org/wiki/Penal_transportation
“The number of convicts transported to North America is not verified although it has been estimated to be 50,000 by John Dunmore Lang and 120,000 by Thomas Keneally. The majority of prisoners were taken in battle from Ireland and Scotland and went originally to New England. Some were sold as slaves to the Southern states” [before the Revolution]