There are many ways to influence public opinion, but propaganda has been a favorite for centuries. Modern propaganda found its roots in the 17th century when Pope Gregory XV sought to gain converts to Catholicism as the Protestant movement grew. Although it began as a religious endeavor, propaganda became political in the 18th and 19th centuries as literacy and freedom of the press expanded exponentially.
Besides Pope Gregory XV, men like Dr. Seuss, Adolf Hitler, and Walt Disney also used propaganda to accomplish various ends. This infographic from wordfocus.com wonderfully depicts ways propaganda was used in the past and how it is stilling being used to influence the world today.