The first, during the change from the 19th to the 20th century, due to the mobility of those displaced by the European industrial revolution and whose effects lasted until the 30's of the last century. And the most recent, which began in the 1970's and continues to the present, made up mainly of Latin Americans and, more specifically, Mexicans, Asians, Central Americans and Caribbean people; which in the case of Mexico is explained by the strong historical ties between Mexico and the United States and by its enormous border: In the case of Mexico, this can be explained by the strong historical ties between Mexico and the United States and by their enormous border: neighborliness, historicity; by the complementary processes of demographic evolution and productive restructuring in both countries; by the precariousness of labor in Mexico and by the existence of a highly consolidated transnational labor market in the North American region. This recent migratory wave is characterized by an accelerated growth rate, which has taken the total number of immigrants from 9.6 million in 1970 to 40 million in 2010.
Since September 1, 2001, a new historical period in migration began, "The Criminalization of Unauthorized Migration", which resulted in: the border fence with Mexico, militarization of surveillance in transit zones, proliferation of anti-migrant legislation. Nevertheless, in the last decade, the migration wave continued to grow and went from 31.1 million people in 2000 to 40 million in 2010, which represents a 28 percent increase in that period.
Immigration in the United States behaves autonomously from the country's labor market, that is, the reasons for immigration are not exclusively economic, although in the 90's the percentage of income grew by 13.2% and employment grew to 22%, however, from 2000 to 2010 the percentage of immigration growth was 13.9%, while the percentage of employment decreased by 0.4%.