Russia and the United States emerged as super powers.
Mungo Park is a Scottish explorer and the first westerner known who was able to travel the central part of the Niger River. Imperialism on the other hand is defined as the practice of a country to increase its power by having control over other parts of the world. The connection between the two ideas is that both are talking about going to other parts of the world and gaining control over it.
The war that erupted in 1898 between the United States and Spain was preceded by three years of fighting by Cuban revolutionaries to gain independence from Spanish colonial rule.