Last year the U.S. experienced something that hasn’t definitively occurred since the Great Depression: More people moved out than moved in. The Trump administration has hailed the exodus—negative net migration—as the fulfillment of its promise to ramp up deportations and restrict new visas. Beneath the stormy optics of that immigration crackdown, however, lies a less-noticed reversal: America’s own citizens are leaving in record numbers, replanting themselves and their families in lands they find more affordable and safe.