The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to

the States respectively, or to the people.

- U. S. Constitution, Tenth Amendment

What was the purpose of this amendment?

1. The states respectively, or to the people.

2. The purpose of the amendment was  intended to confirm the understanding of the people at the time the Constitution was adopted, that powers not granted to the United States were reserved to the States or to the people.

the answer is hope this you.

nothing certain is known about what happened, but it seems that the country declined gradually, perhaps due to bad government, or, more likely, due to a series of bad harvests, which resulted in widespread and recurrent famine.