Immigration Restrictions
In recent decades, most immigration has been through family preferences, with the main sources of immigration being (1) the immediate relatives of U.S. citizens, such as spouses, children, and parents and (2) family-sponsored preferences. Other immigrants have become legal permanent residents through employment-sponsored preferences, being admitted as refugees or being granted asylum, and a diversity lottery for underrepresented countries.
As shown in the charts below, immigration from Asia has been far greater than immigration from Europe in recent decades, and immigration from Asia has sometimes exceeded that from other parts of North America.