Studies have always shown it takes about 3 generations for full assimilation.The sociological studies have shown that true immigrants that go through the process assimilate quite quickly into American Culture. The same studies show that groups like the Mexicans and South Americans have no plans to assimilate, they view it as living here and bringing as much of their culture with them. Just go to Southern California or Texas and this is pretty obvious. We presently are bringing in large blocks of Muslims, many through refugee programs. They not only do not want to assimilate, they want us to change to accommodate their culture. Amnesty will be a disaster and if its true goat boy is going to make it 35 million the fabric of our country will tear and you will see groups form in armed camps against one another, count o it.
Assimilation, sometimes known as integration or incorporation, is the process by which the characteristics of members of immigrant groups and host societies come to resemble one another. That process, which has both economic and sociocultural dimensions, begins with the immigrant generation and continues through the second generation and beyond.
Although the experiences of European groups coming to the United States in the early-20th century suggest that full assimilation generally occurs within three to four generations, no fixed timetable governs completion of the process. For example, recent historical research by sociologist Sharon L. Sassler on European immigrants to the United States has shown that, in 1920, the educational attainment of even third-generation Irish and Germans lagged well behind that of whites who had been in the country more than three generations.
Indeed, groups may vary in the apparent incompleteness of their assimilation for a number of reasons, including the level of human capital (education) they bring with them and the social and economic structure of the society they enter...
http://www.migrationpolicy.org/article/assimilation-models-old-and-new-explaining-long-term-process