Italians were not very much represented in the first groups of immigrants that came to the United States. There were very few Italians in the US for most of the 1800s. However, in the late 1800s, a wave of Italian immigrants came to the United States. They were one of the major groups that comprised the “New Immigrants” of the time period from roughly 1880 until World War I.
Whenever there is a massive migration from one place to another, there are said to be both “push” factors that make people want to leave one place and “pull” factors that draw them to a second place. In the case of the Italian immigrants, there were push factors that made Italy look bad and pull factors that made the US attractive.
The push factors were largely economic. Southern Italy had never been a very rich country, and in the late 1800s things got even harder. There was a disease that hit grapes, one of the major industries of the area. There was a tax on basic foods such as flour that raised the cost of living. There was a population boom that made it harder for people to live. All of these factors “pushed” Italians out of Italy.
The pull factors were also economic. The US was a good place to find work at that time. For one thing, the Civil War had killed many men, leaving something of a labor shortage. For another, the US was booming. The railroad network was being built, requiring huge numbers of laborers. The US was industrializing, and there were many jobs in factories.
These factors combined to push Italians out of Italy and pull them to the United States in the late 1800s and early 1900s.