Four major principles underlie current U.S. policy on permanent immigration: the reunification of families, the admission of immigrants with needed skills, the protection of refugees, and the diversity of admissions by country of origin. These principles are embodied in the Immigration and Nationality Act (INA). The INA specifies a complex set of numerical limits and preference categories that give priorities for permanent immigration reflecting these principles. Legal permanent residents (LPRs) refer to foreign nationals who live permanently in the United States.
During FY2010, a total of 1.0 million aliens became LPRs in the United States. Of this total, 66.3% entered on the basis of family ties. Immediate relatives of U.S. citizens made up the single largest group of immigrants—476,414—in FY2010. Other major categories in FY2010 were employment-based LPRs (including spouses and children) and refugees/asylees adjusting to LPR status—14.2 percent and 13.1 percent, respectively. About 13.3 percent all LPRs come from Mexico, which sent 139,120 LPRs in FY2010.