Since the founding of the United States, there have been three main waves of immigration. These waves have consisted of different types of people and have occurred in different circumstances. However, they have generally had similar impacts in some ways.
First, all of the waves of immigration have served to make American society more diverse. They have brought different customs and different attitudes to the United States. Just to take one obvious example, they have introduced new foods to the United States as Italian food came with Italians in the late 1800s and Mexican food came with the influx of Hispanics in the late 20th century.
Second, the waves of immigration have brought new workers for the American economy. The immigrants have tended to take lower paid jobs that were unpleasant and/or dangerous. This has helped the American economy as it has allowed “natives” to move up the economic ladder into more lucrative positions.
Finally, the waves of immigration have tended to bring about a nativist reaction on the part of “natives.” Each time there is a large influx of immigrants, many natives feel that the country is being threatened. They worry about the dilution of American values and they worry that the new immigrants will not assimilate.
All of these impacts have been common to the various waves of immigration to the US.