South: This population increase is due to the significant need of better living that people wanted from the mexico and puerto rico area of the world. Do the the number of illegal immigrant coming into this country from the south, the need to reproduce to give a better living to their children became a reality. Imagreates crossed the boarder into the south to find better work and wages in order to take care of their families. This lead to a boom of foreign born population increase from the 1990's tp 2000.