Par exemple :
Immigration is a demographic phenomenon that has generated significant population increases and cultural changes in the history of the United States. Immigrants arrived at a rate of more than one million per year during the first decade of the 20th century and about one million per year during the last decade. Immigration was significantly reduced from 1915 to 1965, partly due to the depression of the late 1920s and 1930s and various restrictive measures. Today's immigrants come from countries other than those of the turn of the century and are scattered in a larger number of urban centres. However, their arrival at the beginning of this century raises some of the same questions as at the beginning of the previous one.
Since John Fitzgerald Kennedy's book published in 1958, the phrase "immigrant nation" has been constantly used as a symbol of national identity in support of the ideology of the famous "melting pot" but also of political decisions.
