Based on Brian Burrough's nonfiction book "Public Enemies: America's Greatest Crime Wave and the Birth of the FBI, 1933-34" Public Enemies is set during the great crime wave of 1933-34, when the government’s attempts to stop Depression-era criminal legends such as John Dillilnger (Depp), Baby Face Nelson and Pretty Boy Floyd transformed J. Edgar Hoover’s FBI into the country’s first federal police force.