A lot of elements contributed into winning World War II: Britain refusing to make peace with Nazi Germany after the fall of France along with the Chinese and Soviets willingness to suffer millions of deaths. But World War II was a war between the factories; whichever side could produce the most military equipment would win. The deciding factor in World War II was the fantastic industrial output of the U.S.

Polio was one of the scourges of the 20th century. And it mainly struck children. All of a sudden a person contracted polio and suffered terribly for several days; sometimes they recovered, sometimes they died, and sometimes they were left permanently disabled. The most famous polio victim of all time, Franklin Roosevelt, hid his disability from the public. But this story has a true hero: Jonas Salk, who developed a vaccine which led to the almost complete eradication of this dreaded disease. And Dr. Salk never patented the vaccine or earned any money from his discovery.

Wars are never solely military questions. They always involve politics and the will of the people. This episode outlines America's war in Vietnam and explains why the U.S. lost, including the limitations imposed by the American public and the realities of the Cold War.