I think that the colonists split from England because their freedom was diminished, I believe that the colonists also wanted spiritual freedom and social freedom, also England was pretty crowded and loaded with disease. After the revolution, they did receive what they wanted.
The option that does not explain why a large part of the Great Plains became known as the "Dust Bowl" would be that "<span>The soil of the Great Plains was too rocky to support farming," since the soil was (usually) relatively fertile. </span>
