One projection of the foreign-born population in the United States is that it will rise steadily to 58 million by 2024:

The full report has some interesting data on immigration as well as the methodology behind estimating some of the figures. And, the report notes that these projections assume consistent rates of growth with no policy changes, both unlikely occurrences. Predictions like these are hard to make. At the same time, this is a reminder that large flows of immigrants into the United States is not just a historical fact kids learn in history class but rather is an ongoing phenomenon.