The Immigration Act of 1917 expanded the classes of foreigners excluded from the United States, according to the Encarta Online Encyclopedia.  The law created an Asiatic Barred Zone which included most of Asia.  Immigrants who came from this region were not allowed into the United States.  Aliens who did not reach certain mental, moral, physical, or economic principles were also not let into America. 

The Immigration Reform and Control Act was passed in 1986 because there had been a flow of illegal immigrants.  This act made criminal laws tougher for people who provide work for illegal immigrants.  It also refused to give welfare benefits to illegal aliens.  This law allowed immigrants to request a legal status if they could verify that they came into America before 1982. 

The Immigration Act of 1990 set up a yearly maximum of 700,000 immigrants for the next three years, and a maximum of 675,000 immigrants for every year after that.  Refugees were not included in these numbers.  Another yearly number of 140,000 was set up for immigrants with job skills desired in America.  The number of immigrants who came from countries that had not sent many immigrants in previous years was set at 40,000 to 55,000.  Immigrants who had invested more than one million dollars in business ventures, which created new jobs for Americans, were preferred.