Millions of aliens want to live and work in the United States and enjoy the benefits of U.S. citizenship, but only a fraction of them can. Congress sets numerical limits on most types of immigrant visas, under the theory that the country can realistically absorb only so many new people. The 1995 annual ceiling was 675,000, with flexibility for some categories. In law, aliens granted visas are said to have obtained entry. An alien might cross the border, but still be determined by authorities not to have entered the country.
Entry means legal admittance and the freedom from official restraint.
Denial of entry is called exclusion. Dating from the earliest attempts to control immigration, this controversial concept holds that it is not in the national interest to admit some persons. Far-reaching grounds bar applicants for reasons related to health, crime, national security, and other variables. As part of reviewing applications for visas, consular officials decide whether any of the grounds for exclusion apply. If the officials decide that none do, a visa may be granted, but entry is still not certain.