I want to preface this by stating that much of what I've found is based on legends which may or may not be true. However, it appears there is at the very least some twisted truth in the telling of the Missouri doctor who allegedly stole corpses and at one time owned Mark Twain Cave in Hannibal.
This is the story of Joseph Nash McDowell. As Wikipedia states, he was one of the most well-known and respected doctors west of the Mississippi in the mid-1800's. There's one important aspect of Dr. McDowell's life which is where the legend begins and truth is hard to confirm. Dr. McDowell was alleged to steal corpses.
I have attempted to corroborate this legend and determine truth from myth from multiple sources. Here's a snippet of what Dr. McDowell is alleged to have done in regards to snatching corpses:
Dr. McDowell believed the practice to be necessary in order to advance medicine and his own personal understanding of the human body. During his time teaching at the medical school, he not only encouraged but also required that his students perform at least one human dissection before their graduation. This illegal practice served as a form of bonding for the students; with the practice being strictly taboo to most of society they had only each other with which to discuss what they had done and how it impacted their education.
Believe it or not, the doctor's story gets stranger. It's important to note that this comes under the heading of "Rumors and Folklore". Dr. McDowell's daughter Amanda sadly passed away at a young age and the legend said the doctor interred her in Mark Twain Cave in Hannibal in a copper canister. Here's what Wikipedia says about what happened:
McDowell believed that traditional burial "stifled the soul"...this was his aim when interring his daughter in a container of preserving alcohol, kept secured in his cave workspace in Hannibal, Missouri. However, when McDowell learned that some locals had been daring each other to break into the cave, and disrespecting his child's remains by opening the copper coffin to scare themselves with ghost stories, the Dr. had the body removed
The rumors/legend is this was done by a young Samuel Clemens and led to the telling of Injun Joe and the hidden "treasure" in Mark Twain Cave.
I have confirmed these stories through several different sources including a book called Missouri's Mad Doctor McDowell: Confederates, Cadavers and Macabre Medicine by Victoria Cosner and Lorelei Shannon. Lindenwood College also had an article including these allegations against Dr. McDowell written by Luke Ritter called Anatomy, Grave Robbing and Spiritualism in Antebellum St. Louis.
I highly recommend reading the backstory of Dr. McDowell on the Mark Twain Cave website. Their story confirms he owned Mark Twain Cave for a period of time and that he "was a brilliant surgeon, who needed the temperate quiet solitude of such a place for experimentation of dead bodies."
Somewhere in the middle of all the stories and legends is some truth. It's obvious that at the very least Joseph Nash McDowell was one of the most intriguing characters in the early 1800's Missouri.