What imperialist nation had the most impact on the world from 1750-1900?
Undoubtedly Great Britain. The British Empire was, for most of that period, far and away the largest and most powerful empire in the world.
Before World War 1 Germany clashed with both Great Britain and France over conflicting imperialist ambitions in?
All of the Imperialists in history? Firstly, you have the Carthaginians, then the Greeks, Macedonians, Persians, Romans, Aztecs, Turks, Arabs, Mongolians, Spaniards, Portuguese, Holy Roman Empire (largely Germanic), French, Dutch, British, Russians, Hungarians, Germans, Chinese, Japanese, United States. Pretty much any country given the power, development, and resources at some point in their history will become imperialist, or at least many will. I'm sorry if I have left out any significant imperialist people/nation, but this…