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. 

In 1924 the Immigration Act was passed.  It is also called the National Origins Act.  This act decreased the number of immigrants who could enter the United States that were supposedly unfavorable.  Asians were considered undesirable at this time, so most of them were not allowed to enter America.  The number of immigrants who could come from Great Britain, Germany, and Ireland was increased.  The number of immigrants who could come from Russia and Italy was also decreased. 

Many immigration laws have been written over the years.  The immigration law that sets the basic guidelines for all of the other immigration laws is the Immigration and Nationality Act.  This law was written in 1952.  This act contains all of the guidelines for temporary aliens and permanent aliens who wish to work in the United States.  It also specifies if an alien is qualified to work in the United States. 

In 1965 new amendments were passed, changing the Immigration and Nationality Act.  Limits were put on the number of immigrants who could come from the Eastern Hemisphere and Western Hemisphere each year.  From the Eastern Hemisphere, close relatives of American citizens, refugees, and immigrants who had skills needed in America were preferred.   These limits did not include husbands, wives, children, or parents of American citizens.