​How a team without a doctor navigated illness, injury, and survival in the American wilderness
 

When President Thomas Jefferson commissioned the Lewis and Clark Expedition, he understood a stark reality: once the Corps of Discovery left the St. Louis area, there would be no access to hospitals or trained physicians. To prepare, Jefferson sent Captain Meriwether Lewis to Philadelphia for intensive study—not only in mapmaking, botany, and zoology, but also in frontier medicine.
 

A Crash Course in 19th-Century Medicine

Lewis trained under Dr. Benjamin Rush, one of America’s most influential physicians.

Dr. Benjamin Rush, signer of the Declaration of Independence and pioneer of mental health care, was Lewis’s key mentor. In addition to helping curb Philadelphia’s 1793 yellow fever outbreak, Rush was renowned for his research in psychiatry. His 1804 publication Medical Inquiries and Observations Upon Diseases of the Mind broke ground by focusing on causes—not just symptoms—of mental illness.

For three months, Lewis learned how to treat wounds, fevers, and digestive ailments—often through bleeding, purging, or administering powerful compounds. He also left Philadelphia with something even more practical: a set of Rush’s personal health rules and a portable pharmacy tailored for survival.
 

Dr. Rush’s Health Advice for the Trail

In a June 1803 letter to Jefferson, Rush offered specific guidelines to preserve health on the frontier:

• Rest early at signs of illness: "Do not attempt to overcome it by labor or marching."

• Fasting and fluids: Often enough to curb a fever.

• Purge at first signs of constipation or appetite loss.

• Marching tips: Eat sparingly during long marches to avoid fatigue.

• Wear flannel next to the skin, especially in damp weather.

• Avoid spirits; sugar or molasses with vinegar is a better drink.

• Wash your feet daily in cold water to toughen them.

• Lie flat for fatigue relief—two hours horizontal is better than a longer upright rest.

• Wear flat shoes to reduce strain on leg muscles.

While some advice may sound odd today, the results were remarkable: only one member of the Corps died, likely from a ruptured appendix—something even modern medicine would struggle to treat in the wilderness.
 

The Corps’ Medical Supplies

Rush’s kit cost $90.69 and included an arsenal of 19th-century remedies:

• Lancets for bleeding

•  Forceps and tourniquets

•  Laudanum (opium)

•  Peruvian bark (quinine) – ~3,500 doses

• Jalap and calomel – used as purgatives

• Tartar emetic – powerful vomiting agent

• Gonorrhea and enema syringes

• Niter (saltpeter), Glauber salts

• Mercurial ointment – a common remedy, though toxic by today’s standards
   

⚡ Featured: “Thunderclappers”

The most famous remedy was Dr. Rush’s patented purgative pills—a potent blend of calomel (mercury and chlorine) and jalap. Nicknamed “Thunderclappers” for their explosive effect, these were widely used throughout the journey. As historian Stephen Ambrose quipped, “If one pill didn’t work, you took two or three.”
 

Medicine on the Move: Excerpts from the Journals

Health challenges were frequent—and well documented.

📖 June 3, 1804 – Clark: “I have a bad cold with a sore throat.”
📖 June 17, 1804 – Clark: “The party is much afflicted by boils and several have the deassentary which I contribute to the water.”
📖 July 4, 1804 – Ordway: “Fields got bit by a snake, which was quickly doctored by bark by Cap. Lewis.”
📖 July 7, 1804 – Clark: “One man very sick, struck with the Sun. Capt. Lewis bled him and gave Niter...”
📖 October 18, 1806 – Lewis: Shot by accident, he treated himself:

“I dressed my wounds myself... the pain I experienced excited a high fever and I had a very uncomfortable night.”
 

Mental Health: A Silent Struggle

Though not often recorded, Lewis’s mental health has long been a subject of historical concern.

In Dear Brother: Letters of William Clark to Jonathan Clark, edited by James Holmberg, Clark wrote that Lewis was suicidal and in a “state of derangement” during his 1809 journey to publish the journals. Days later, Lewis died of gunshot wounds, presumed self-inflicted, near Grinder’s Stand in Tennessee.

Was Jefferson aware of Lewis’s emotional struggles? Did he send him to Rush partly for his pioneering work on mental illness? We may never know. No correspondence directly confirms this theory—but it remains a compelling question.
 

Top 5 Strange Cures on the Trail

Medicine in the wilderness wasn’t for the faint of heart. Here are five eyebrow-raising remedies the Corps relied on:

1. Dr. Rush’s “Thunderclappers”
   These infamous pills packed a double punch of calomel (a mercury compound) and jalap root. Designed to purge the body, they were often administered in multiples. The result? Sudden and powerful “cleansing” that earned them their explosive nickname.

2. Bloodletting for Sunstroke
   When a man collapsed from heatstroke, Lewis treated him by bleeding him with a lancet and administering potassium nitrate (saltpeter). To their relief, the soldier revived—though modern medicine would definitely not recommend this approach today.

3.  Snakebite Poultice
   On July 4, 1804, after a snakebite, Captain Lewis applied a poultice of tree bark and gunpowder. The remedy worked well enough to make it into the journals—but it’s definitely not in your local first-aid manual.

4.  Tartar Emetic (to induce vomiting)
   Used to expel toxins or treat fevers, this compound could cause severe nausea. With over 1,100 doses packed for the trip, it’s clear Lewis planned for many upset stomachs—or worse.

5. Foot Washing & Cold-Water Fortification
   Dr. Rush believed daily cold-water foot baths would toughen the men’s feet against the elements. He also recommended spirit washes after chilling and sleeping flat on your back for recovery.
   
   Researched by: Scott Clark, Museum Historian for the Glore Psychiatric Museum