Which native american culture group built mounds for protection and ceremony?

Historians are concerned with the accuracy of their writings and readings but are also aware of the inability of authors to know every angle of every story biases, perspectives, beliefs, and a variety of other differences history being told by one person at a time no one being totally accurate, as hard as we try really need on this, and you^^

Which of the following acts or treaties tried to american indians?

Which is proper hierarchy or leadership roles in the senate from lowest to highest