It came about when a dentist, Josef Lascaux, built a machine and sold the treat to patients in his Louisiana office. It's believed that he's the one who coined the permanent name.
Following the invention of machine-spun cotton candy, it was finally introduced to a wide audience at the World’s Fair in St Louis. At the time, it was called "fairy floss."
Can you believe it? Dentist William Morrison and confectioner John C. Wharton are credited for the invention of machine-spun cotton candy.