Seventy-nine years before American troops launched the landing operation at Inchon during the Korean War, U.S. troops were involved in another amphibious assault in that corner of Korea. The Korean Expedition of 1871 sought to open trade with the insular Asian nation—and avenge the destruction of an American ship crewed by kidnappers and pirates. Fifteen American sailors and marines won the Medal of Honor in the brief war, the first such medals awarded for service overseas. Though their actions were skillfully executed, the lamentable political context of the conflict may explain why their deeds are not exactly celebrated in the history textbooks.

The “Hermit Kingdom” of Korea was renowned for its isolationist policies, a result of it having sustained repeated invasions from China and Japan. By the 1860s, the ruling Joseon dynasty was in no way encouraged to change its ways by the example of China, then a nominal ally. Western influence in China had seriously undermined the Chinese Qing dynasty’s authority, and led to two humiliating defeats in the Opium Wars begun in 1839 and 1856. The British felt perfectly justified in going to war to defend their right to a free trade in dope in Chinese territory. Furthermore, the spread of Christianity in China, transmitted by European missionaries, indirectly led to the even more calamitous Taiping Rebellion.

As a result, Korean regent Heungseon Daewongun instituted a crackdown that killed thousands of native Christians and all but two of the Catholic missionaries in Korea—leading to heightened tensions with France, whence many of the missionaries came.

Traders who attempted commerce in Korea were more politely shown the door. The Korean government exchanged cordial welcome to the USS South America—the first official contact between the two nations—and repatriated shipwrecked U.S. sailors on several occasions. However, American ships had intervened repeatedly on behalf of the British during the Second Opium War, and the Korean government remained wary of their presence.

In 1867, the crew of a heavily armed U.S. ironclad steamship attempted to force the issue, while involved in the Taiping Rebellion and acts of piracy.

On August 9, 1866 it sailed from Tianjin, China under command of three Americans, including Captain Page and owner Preston. The crew also included Welsh missionary Robert Thomas, fifteen Chinese and Malaysian crewmen, and a British pirate. The ship’s hold was full of cotton, tin and glass. It was its owner’s ambition to open trade with a closed-off Korea.

The General Sherman began sailing up the Taedong River on August 16, its crew handing out Bibles and impressing Korean villagers along the way. Local officials repeatedly informed Captain Page he was not authorized to trade in Korea and should not proceeded further upriver, but the American sailed his vessel onward towards Pyongyang. Finally, regent Daewongun, believing the General Sherman to be a French ship seeking to avenge the deaths of Catholic priests, told Governor Park Gyu-su to inform the ship’s crew that they must either leave or die.

By then, the General Sherman had run aground, its crew having misjudged the depth of the river due to a temporary rain swell. On August 27, attempting to forage, the crew sent out a dinghy to which was intercepted by a junk carrying Yi Hyon-ik, the deputy of Governor Park, with two guards—all of whom were subsequently taken hostage by the boat’s crew. When Park attempted to negotiate for their release, the kidnappers demanded a ransom of rice, gold, silver and ginseng. A crowd of civilian onlookers grew so incensed they began pelting the vessel’s crew with arrows and stones and even hwajeon “fire arrow” rockets. In the ensuing chaos, Korean Sergeant Park Chongwun managed to hijack a dinghy and rescue Yi Hyon-ik. Meanwhile, the boat’s twelve-pound cannons began blasting the civilian crowd with shrapnel, killing seven.

By September 2, the regent had dispatched state troops armed with matchlocks to destroy the stranded vessel. First, the Koreans tried cobbling together an armored “turtle boat” protected by metal sheeting and cowhides, with a narrow slit concealing a cannon. However, the turtle boat’s gun could not penetrate the iron ship’s armor, while the American ship’s deck guns killed one of the boat’s crew in return.

The Koreans then tried roping together three small boats loaded with firewood, saltpeter and sulfur, lighting them on fire, and sending them drifting off towards the General Sherman. While the first trio of boats missed its target and the second bounced off, a third brace of fire ships set the American vessel ablaze. The crew abandoned the flaming ship, and were soon hacked to death by the enraged mob on the shore. Reverend Thomas’s death, supposedly while handing a Bible to his executioner, was later cast as an act of martyrdom.

The General Sherman’s guns were subsequently salvaged, its anchor hung up at Pyongyang, and its defeat celebrated in the capital of Seoul. Unsurprisingly, the incident remains well memorialized in North Korea today. State textbooks even claim an ancestor of Kim Il-sung participated in the attack, and until recently, the captured U.S. spy ship USS Pueblo was moored at the site of the General Sherman’s grounding.

Inquiring Americans Want to Know: What Happened to the General Sherman?

However, U.S. officials in China were never directly informed of the General Sherman’s fate. This was in part due to the Koreans believing the vessel to be of French or British origin, and also over concerns that doing so might invite retribution or a demand for reparations. In fact, according to some accounts, Korean shipwrights salvaged the General Sherman and recommissioned it into Korean service, before the boat wound its way back to the United States through a convoluted chain of circumstance.

Regardless, the vessel’s fate remained a mystery in the United States for the next five years. Inquiries by visiting U.S. Navy officers in 1867 and 1868 were stonewalled by Korean officials. As it happened, subsequent events had further deteriorated the Koreans’ sentiment towards Westerners.

Two months after the General Sherman incident, a French fleet of seven warships did actually show up, establishing a blockade of the Han River and dispatching a landing force to the size city of Ganghwa on the island of the same name. However, Korean troops successfully repelled the invaders at the fortified monastery of Jeongdeung-sa, and the French troops ultimately had to beat a hasty retreat from an increasingly untenable position. They sacked Ganghwa city on their way out, stealing cultural relics and attempting to make off with a large engraved bell—before encroaching Korean troops forced them to abandon the booty as they fled back to their ships.

Then, in May of the following year, German merchant Ernst Oppert barely escaped Korea with his life after a misfired attempt to blackmail the Korean regent into opening trade with the West by holding the interred remains of the regent’s father hostage. You can’t make this stuff up! These incidents inspired the Joseon dynasty to mobilize Koreans against future potential invasions.

Five years later, the State Department decided to send Frederick Low, the ambassador to China along with the U.S. Navy’s Asiatic Squadron, to investigate the General Sherman’s disappearance—and also attempt to negotiate a trade treaty with the Korean government similar to the one Commodore Perry had pushed Japan into adopting.

Low’s flagship would be the three-mast screw frigate USS Colorado, armed with forty-four guns. These were supplemented by two eleven-gun sloops of war, the Alaska and Benici, and two paddle-wheel steamers, the gunboat Monocacy and the armed tug Palos. These last two vessels were the only two capable of sailing upriver. The squadron also carried a company of 109 U.S. marines. Clearly the Americans expected trouble, but Low’s intent was to negotiate matters peacefully if possible.

The Asiatic Squadron departed from Nagasaki, Japan, on May 16 and set anchor at Inchon a week later, making peaceful contact with armed villagers on Wolmi Island before sailing to Ganghwa a week later. Finally, on May 30 and 31, the squadron made repeated contact with low-level Korean officials on a junk. The Americans professed that they came in friendship, hoping to sign a trade treaty and also survey the nearby rivers. The officials politely explained they lacked the power to negotiate and that the government was not the least interested in a trade treaty. The Koreans felt they had gotten along fine without treaties with the United States for centuries, so why should that change?

On June 1, the Monocacy, the Palos and three small cutters set sail down the Han River on a river charting expedition heading towards Seoul. As they made their way, the American boats approached a bend in the river overlooked by three forts. They could see troops lining the ramparts. As the U.S. ships made their way around the bend, a shot cracked through the air, signaling the commencement of an ambush. The Korean soldiers rained heavy fire on the American ships with antiquated cannons and enormous tripod-mounted jingal matchlock muskets. However, even as hot metal sprayed the water around the American ships, it inflicted little damage—the old weapons were inaccurate and could not easily adjust their aim.