What methods did Europe use to achieve imperial control in the 19th century?

How did European nations come to dominate much of the world during the 19th century?? How did the other countries react to the european imperialism?What methods did Europe use to achieve imperial control in the 19th century?
They took over Africa. The natives there were easy target because they didn't have the type of weapson that the Europeans had. I can't remember the name of it, but there was this huge fight that slaughtered a ton of africans but only a couple europeans. So basically all the countries in europe took a part of Africa for themselves. The other countries wanted the imperialism as well, such as with Germany. Their desire to be an empire is what helped to cause the world war.