Were Americans welcoming to Irish immigrants

no infact according to the internet the irish were the most feared terrorists

Not really

Explanation: The Irish were a majority immigrant group, which means that they were generally disliked by the common American. They were a totally different religion than most Americans (they were Catholic, not Protestant like most Americans). They were so disliked by some that a political party, the American Party, was formed. Nationalists (people who supported an all-American country with no immigrants) formed this party in retaliation to the growing immigrants numbers, especially in retaliation to the Irish and the German peoples.