Hunger basically.
Due to poor weather, the potato crop failed several years running. Food got scarce and expensive so people moved out.
Irish <Fenian> immigration began and escalated thereafter.
Most of the Immigration was caused by the potato famine, but some were caused when their king had switched to a England church because of his marriage. That caused England to be in control of Ireland which left them weak. Another when the black plague had spread to them from England and the Irish were mad at them cause now, England had made most of their troubles.
the anwnser was Irish and German
The largest influx of the Irish started in 1845/6 and ran for 15-20 years. It was caused by Irish families trying to escape the Potato Famine which was ravaging Ireland at that time. Earlier, in the period 1817-25, large numbers of Irish laborers came over to work on the construction of the Erie Canal in New York State. Those were the two big 'jumps' in the Irish immigration.
potato blight
There was a huge immigration of Irish citizens to the USA during the potato famine.
The Irish Jews were such a small population (<1,000 people) that there really was no wave of Irish Jewish immigration to America. Additionally, since most Irish Jews lived in the cities, they were not subject (as strongly) to the Irish Potato Famine, which was responsible for the largest percentage of Irish immigration to the US.
Irish & German -Apex (:
Irish and german
Immigration Act of 1990
the low money caused the immigraton system.
The basic food crop of Ireland was potatoes. There was a "Potato Famine" from 1845 to 1852 caused by a blight that devastated the potato crops nationwide in Ireland. Over a million Irish starved to death, and a huge immigration to the USA by over a million Irish followed, looking for another place to start over, and work to earn money to eat, as simplistic as that sounds.