Since the early years in their histories as independent nations, the United States and its southern near–neighbors have been linked through their foreign policies and the movements of their peoples. In the nineteenth century, the acquisition of the Floridas and the conquest of northern Mexico by the United States led to substantial movements of people. Later in the same century, the U.S. conquest of the remnants of Spain's American empire contributed to the hispanization of the population of the United States.
In the twentieth century, U.S. immigration policy turned generally restrictionist. Foreign policy concerns, however, led the government to permit and even, for a time, to stimulate Mexican immigration to the United States. Consistent with its policies toward the Soviet bloc, the U.S. government also stimulated migration from Cuba for a certain period. These U.S. policies have been supplemented by those determined and ingenious people who, drawn by the promise of the words inscribed on the Statue of Liberty, have entered the United States illegally. As a result, the United States is already the fifth largest Spanish–speaking country in the world.