Jeffrey Passel, D’Vera Cohn and Ana Gonzalez-Barrera write for the Pew Research Center:
The largest wave of immigration in history from a single country to the United States has come to a standstill. After four decades that brought 12 million current immigrants—more than half of whom came illegally—the net migration flow from Mexico to the United States has stopped—and may have reversed. read summary here or full Pew Research report here.