Population distribution in both countries is very uneven, with the greatest concentrations falling within several hundred miles of the the east and west coasts. Both countries were settled by immigrants and people from Africa and their descendants, and both continue to accept hundreds of thousands of immigrants yearly. Now the source of immigration stream is shifting from away from Europe and Africa and toward Middle and South America and Asia. As a result, the cultural diversity of both countries is rising. 18 percent of U.S. population change residence every year.
Interregional shift is towards the south and west.
The geographic center of population is west of the Mississippi and is likely to continue to move in that direction. A steady stream of immigrants have assimilated into the culture. People maximize their proximity to existing economic opportunities, showing little resistance to relocating as nation s economic fortunes change favoring different places over time. This effects growth of cities. The population is moving from rural to urban.