Final answer:
The two regions with the largest number of U.S. immigrants from 2006 to 2009 were Latin America and Asia.
Step-by-step explanation:
From 2006 to 2009, the two regions that provided the largest number of United States immigrants were Latin America and Asia. This period marked a significant shift in the patterns of immigration to the United States, with immigrants from Europe constituting a smaller fraction compared to earlier in the century. By the 2000s, data shows that about half of U.S. immigration originated from countries in the Americas, particularly Mexico, and about a quarter from various countries across Asia. The change in source countries for immigration illustrates the dynamic nature of migration trends and underscores the multicultural demographics of the United States.