You must be talking about the assassination of Archduke Franz Ferdinand of Austria. This was an event which triggered the start of WWI.
It's a treaty of peace between the United states of America and Mexican Republic signed on February 2, 1848 in the Villa Guadalupe. Because of this treaty of peace the war between two parties ended that dat. the said location of the treaty is the place where the two countries engulf.
There are actually a lot of proof of how Einstein lead many people to question the nature of reality. Einstein knows how people loves to ask. Most of the people are curious about on what is going on in their life. Einstein was not just a scientist, Einstein was actually a philosopher too.