From Ohio History Central
Many scholars credit Niles, Ohio, resident Harry Mosley Stevens with inventing the hotdog. By the early twentieth century, Stevens resided in New York City, New York, where he oversaw the ice cream and soft drink concessions for the New York Giants, a professional baseball team. Historians disagree on the date, but in either April 1901 or April 1906, Stevens began to sell wieners in a bun. According to the story, Stevens realized most people had no desire to eat ice cream in the cool temperatures of April, so Stevens wanted to find a new product that would be more appetizing.
Stevens initially called his product "red hot dachshund sausages," because the wiener resembled a dachshund dog. Supposedly, Thomas Dorgan, a cartoonist for The New York Times Journal drew a cartoon where he referred to Stevens' dachshund sausage as a "hotdog." No record of the cartoon has been found by scholars. Unfortunately for Stevens, at first, many people believed that the dachshund sausage or the hotdog really contained dog meat. Eventually people realized otherwise, and the hotdog became one of the most popular foods in the United States.