The reason the population is so unbalanced is because the states on the east and the east coast have older cities, big capitals, and arable land perfect for growing food. on the east coast, there is more arable land as well as water and beaches. in the middle, however, is hot and dry. if you look at a map of the U.S. U.S. sattelite view, you can see that it's just mountain ranges and deserts, which is not desirable for human life.
