On this day, November the 11th, in the year of 1918, the First World War (known then as the “Great War”), one of the deadliest wars in human history (fifth) (Borgen Project), came to an end.

As the war raged on, both sides of the conflict started to lose steam. But late in the war, the United States joined on the side of Great Britain and France against Germany due to the Germans sending a message to Mexico, saying they should invade the U.S. so they would stay out of the war in Europe.

The U.S. joining, among other factors, helped turn the stalemate of the war in the favor of the Allies, leading to Germany signing an armistice to surrender and end the war. 

Today, the day is celebrated around the world, either as Veterans Day (like in the U.S.) or Armistice Day (like in the United Kingdom and France) (BBC) (Britannica).