Well some rivers in Europe are used to transport goods. Sometime people even travel on them. River also can provide power.
South Carolina was the first because they though that their way of life was threatened from the election of President Abraham Lincoln.
C. Fur trading because they used to use the skins of animals such as beavers
The Indian Removal Act was signed by Andrew Jackson and it was a law that was supposed to call for the "voluntary" removal of Indians from their land. The United States wanted to expand and use their land, and ended up forcefully removing them and resulted in the removal of most Indians from the states altogether. Hope this helps! :)