Answer:
The historical circumstance that led to this development was the European exploration and their desire for raw materials that eventually led to Imperialism.
i have no idea if its the answer i still have to catch up with my maps hehehe
Because the people of Kansas were allowed to vote whether the new state should be slave or free.This focused a lot of attention on Kansas, and terrorists from <span>both sides crossed into the state to interfere with the voting.</span>
Imperialism , let me know if if right
