What were some important events that happened around the 1930's?

1.)In 1931, the "Star Spangled Banner" becomes the country's official national anthem.
2.)In the 1936 Olympics in Berlin, a black Alabama native educated at Ohio State University, Jesse Owens, wins four gold medals. He breaks Olympic and world records, but German dictator Aldoph Hitler refuses to recognize the American's achievements. Hitler had declared that the superior German Aryan race would dominate the games. He was wrong.
3.)In 1939, the first commercial air flight crosses the Atlantic Ocean, and the helicopter is invented.

Abbasbnne enajenen wkwksnsns aléjense