Hot dogs are called "hot dogs" due to their association with the city of Frankfurt, Germany. The name "hot dog" is believed to have originated in the late 19th century when German immigrants brought their traditional sausages, known as "frankfurters," to the United States.

These sausages were made from a mixture of pork, beef, or veal, and were named after the city of Frankfurt. However, the pronunciation of "frankfurter" by English speakers led to the creation of the term "hot dog."

One popular theory suggests that the term "hot dog" was coined in the early 1900s at the Polo Grounds baseball stadium in New York City. Legend has it that a vendor named Harry Stevens began selling hot sausages in rolls at the stadium. To attract more customers, he started calling them "red hot dachshund sausages."

The term "dachshund" referred to the shape of the sausages, which resembled the long, narrow body of a dachshund dog breed. Over time, the term "dachshund sausages" was shortened to "hot dogs."

Another theory suggests that the term "hot dog" originated from a cartoon drawn by T.A. Dorgan in 1906. The cartoon depicted a dachshund dog inside a roll, and Dorgan reportedly wrote "Get your hot dogs!" as a caption. This cartoon is said to have popularized the term "hot dog" as a reference to the sausages.

Regardless of the exact origin, the term "hot dog" gained widespread usage and became the popular name for the sausages in the United States. Today, hot dogs are enjoyed as a staple food at picnics, barbecues, and sporting events.

References:

1. History.com - Hot Dog: The Surprising Origin of the Food's Name
2. Smithsonian Magazine - The History of the Hot Dog
3. Merriam-Webster - Why Is It Called a 'Hot Dog'?