I believe it's the opposite 180th meridian.
Answer: The Holocaust
Explanation: People say the main reason WW 2 started is because of the Holocaust. There was a large group of men named "The Nazis" and they tried to get rid of all the Jews and people with disabilities they all thought the perfect race is Blonde hair and Blue eyes. The leader of the Nazis you probably heard of him... Adolf Hitler he murdered himself April 30, 1945
Well, i think the answer would be : Standardized weight and measures
Standardized weight and measures first developed by the muslim merchants in Cairo. Before this standard, Length was measured by the length of one's body.
For example to measure silk, the usually used the term such as 1 arm length.
The thing is, many traders started to hire shorter people to measure this to gain profit , making exchange often became problematic
hope this helps
