<span>The overwhelming victory of the United States over Spain in 1898 made the United States a world power. The U.S took control over the Philippine Islands, Puerto Rico, Guam and a few other places. The war was a turning point in that it caused the United States to become an imperialist power. The U.S. had to maintain a large navy to protect its overseas colonies. It put America on what became a collision course with Japan, which was on its own path to imperialism in the Pacific. So the American victory over Spain set the U.S. on a couse of imperialism. I hope that this has been a help to you.</span>
Once all of the southern slaves were free, they fought against the south, helping the union win.
The immediate cause of World War I that made the aforementioned items come into play (alliances, imperialism, militarism, nationalism) was the assassination of Archduke Franz Ferdinand of Austria-Hungary. In June 1914, a Serbian-nationalist terrorist group called the Black Hand sent groups to assassinate the Archduke.
