The use of food delivery bags or containers to transport food dates back to ancient times, although they were not as specialized or standardized as modern food delivery bags. In more recent history, the concept of using insulated containers specifically for food delivery began to emerge in the early to mid-20th century as urbanization and the popularity of home delivery services grew.

While there isn't a specific documented date for the first appearance of a delivery bag, we can trace the evolution through various stages:

1. Early 20th Century: In the early 1900s, there were instances of insulated containers being used in institutional settings like hospitals and military bases to transport meals. These containers were designed to keep food warm during transit and were likely made from rudimentary insulation materials like wool or simple insulating fabrics.

2. Mid-20th Century: By the mid-20th century, with the rise of fast food chains and the expansion of restaurant delivery services, there was an increasing need for more reliable methods to transport food from restaurants to customers' homes. This era likely saw the development of more specialized containers or bags designed specifically for food delivery purposes.

3. Late 20th Century and Beyond: As the food delivery industry continued to grow and evolve, so did the technology and materials used in delivery bags. Advances in insulation materials such as polyurethane foam and the introduction of durable, easy-to-clean fabrics further enhanced the effectiveness of delivery bags in maintaining food temperature and quality.

While the exact date of the first appearance of a dedicated food delivery bag is not pinpointed, the gradual development and refinement of these containers parallel the growth of urbanization, fast food culture, and consumer demand for convenient dining options delivered to their doorstep. Today, food delivery bags are an essential tool in the food service industry, enabling restaurants and delivery services to ensure that meals arrive at their destination fresh, hot (or cold), and ready to be enjoyed.