Ketchup Was Once Sold as Medicine

Before ketchup became the world's most popular condiment, it had a very different reputation. In the 1830s, Dr. John Cook Bennett of Ohio promoted tomato ketchup as a medical remedy for liver problems, diarrhea, indigestion, and bilious attacks. It was sold in pill form and prescribed by physicians.

Tomatoes were actually considered poisonous by many Americans at the time (they're in the nightshade family), so Bennett's efforts also helped popularize tomatoes as food. The modern sweet-and-tangy ketchup we know was standardized by Henry Heinz in 1876, who added sugar and vinegar to preserve the sauce and give it its characteristic flavor.