Indigestion and heartburn have been described for thousands of years, but it was only in the 16th century that the disease peptic ulcer was established by autopsy. At first, only gastric ulcers were identified. In the 18th century, duodenal ulcers, most of which were fatal cases after perforation or hemorrhage, were seen. In the 19th century, when autopsy became a common, even routine, hospital procedure, uncomplicated acute and chronic ulcers were found and then correlated with symptoms. Thus, our current clinical understanding dates from the 1820s, by which time peptic ulcers were being reported in the U.S. It is unclear why gastric ulcers were not diagnosed at The Mount Sinai Hospital until 1873 and duodenal ulcers until 1885. However, after that time both conditions were diagnosed frequently, and they rapidly became common and were treated medically and surgically.