In 1904, a left-wing American feminist called Lizzy Magie patented a board game that evolved into what we now know as Monopoly. But 30 years later, when Monopoly was first marketed in the United States during the Great Depression, it was an out-of-work salesman from Pennsylvania who was credited with inventing it. Louise Hidalgo has been talking to American journalist Mary Pilon about the hidden history of one of the world's most popular board games, and to the economics professor Ralph Anspach who unearthed the story.

Picture: A family playing a game of Monopoly in the 1930s (Credit: SSPL/Getty Images)