World War II Started With German Invasion of Poland 73 Years Ago

German Fuhrer Adolf Hitler salutes as he oversees his military troops during the Nazi occupation of Poland. The Sept. 1, 1939, invasion started World War II 73 years ago. The troops here march in formation toward a wooden bridge, constructed by the Nazis across the San River, near Jarolaw, Poland. The Nazis and Soviets had divided Poland by the end of September 1939. (Hulton Archive/Getty Images)