The main types of art produced by the native americans of the great planes were portable because the tribes of that region were

Nomads

The main types of art produced by the native Americans of the great planes were portable because the tribes of that region were nomads. it makes sense that they made portable art, as they move through the territories, making easy to transport and collect such form of art instead of big pieces that would have been difficult to transport. 

They are discriminated against and made fun of for being foreign

Im pretty sure it is true