Otto Japp was 15 years old when The New York Stock Exchange crashes in what will be called the Crash of '29 or "Black Tuesday", ending the Great Bull Market of the 1920s and beginning the Great Depression. The New York Stock Exchange, is an American stock exchange located at 11 Wall Street, Lower Manhattan, New York City, New York. It is by far the world's largest stock exchange by market capitalization of its listed companies at US$21.3 trillion as of June 2017. The average daily trading value was approximately US$169 billion in 2013. The NYSE trading floor is located at 11 Wall Street and is composed of 21 rooms used for the facilitation of trading. A fifth trading room, located at 30 Broad Street, was closed in February 2007. The main building and the 11 Wall Street building were designated National Historic Landmarks in 1978.
Otto Japp was 25 years old when Adolf Hitler signs an order to begin the systematic euthanasia of mentally ill and disabled people. Adolf Hitler was a German politician, demagogue, and Pan-German revolutionary, who was the leader of the Nazi Party, Chancellor of Germany from 1933 to 1945 and Führer ("Leader") of Nazi Germany from 1934 to 1945. As dictator, Hitler initiated World War II in Europe with the invasion of Poland in September 1939, and was central to the Holocaust.