If you were living in a place where there was bad government, not much employment, famine, religious persucution, and poverty, why would you want to stay in that place? Almost all immigrants experienced these problems in their home countries. They were thinking of a wonderful new country with freedom, good government, chances for jobs, and freedom to do, say, and believe what they wanted. If you were in that situation, why wouldn't you want to come to the United States of America? Here is a list of reasons immigrants might have wanted to come to the U. S.
Sometimes large waves of immigrants came from a certain area because of an epidemic or famine. This was the case with Ireland. In Ireland the potato crop had been ruined by a kind of fungus. Unfortunately, this was the main source of food for people in Ireland. This forced Irish people to at least consider coming to the U. S. As a result, many Irish people immigrated to U. S.