Why did the native americans support the confederate army in the civil war?
they were threatened into serving in the confederate army.
they feared that the union would take away their land.
they wanted to maintain their ability to use slave labor on their lands.
they were promised increased lands by the confederate army.

The correct answer is: They feared that the Union would take away their land.

Explanation:

During the Civil War the Native Americans decided to support the Confederate Army because they feared for their properties. The decision was based upon the fact that their choices were limited to either cooperate and collaborate with the Union, or otherwise loose their land and be forcefully kicked out of their homes. They saw it as the least harmful option, as it wasn't a threat to the sovereignty of Indian nations.