What is the section of the Constitution called that serves as an introductory statement and comes before the actual articles?

I think it is called " The preamble to the Constitution"

Explanation:

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.

this act gave the federal government the power to relocate any native in the east to territory west of the mississippi river.