Why did the Irish Immigrants come to America?
In the times when immigration was heavy, America was a blossoming country, and was said to be the best place to live. It was thought that America had land and jobs to share and that is why America was a popular place to immigrate to.
In the case of why the Irish specifically came, it was most probably the Potato Famine. The Potato Famine left thousands of Irish starving, and without any income. Raising the potatoes was the livelihood of most Irish and when the rot struck, they had no way to pay landlords or pay for food. They were forced to leave in hopes of a better life somewhere else, and since America seemed to be so rich in opportunities, most chose to go there.