The history of U.S. nineteenth century military intervention in Korea included the first American Korean War in 1871, a war noted by its belligerence. Five years earlier, in July 1866, a U.S. Merchant Marine ship, the General Sherman, a heavily armed ship with a mixed crew of U.S., British, and Chinese/Malay, including a Welsh/U.S. Protestant missionary, Robert Thomas, attempted to penetrate Korean waterways in pursuit of trade discussions and Christian evangelization. Denied permission to sail up the Taedong River leading to Pyongyang, the ship defied Korean authorities. Consequently, after four days of fighting, the ship was burned, and the 20 persons aboard killed.
In retaliation, the U.S. Navy and Marines invaded Korea in June 1871 with the warships Monocacy and Palos, three steam launchers, and about 20 support boats, with total crew of more than 1,000 sailors and marines, mostly Civil War veterans. The ships had departed Nagasaki, Japan on May 16. The U.S. Minister to China, Frederick Low, was on board. The expedition was commanded by a Civil War veteran, Admiral John Rodgers, who had had previous Far Eastern experience. Nearly 700 men landed at the Kanghwa beaches (25 miles north of presentday Inchon in west central Korea), partly to resume attempts at trade talks with the "last outstanding scoffer at Western civilization," but also to "avenge the insult to the American flag," and the earlier loss of the General Sherman and her passengers [William Elliot Griffis, "American Relations With the Far East," The New England Magazine, November 1894, pp. 269, 270]. The Koreans again resisted. But the U.S. forces insisted on vengeance and, in two days of heavy fighting, June 10-11, 1871, destroyed five forts and inflicted as many as 650 casualties on the defending Koreans, while suffering only three casualties of their own. The U.S. forces departed on July 3, obviously not having succeeded in establishing any trade with Korea.
In all of the Nineteenth Century, this was the largest U.S. military force to land on foreign soil outside of Mexico and Canada until the "Spanish American" War in 1898. This intervention created heightened anxieties among the Japanese about aggressive U.S. intentions in Asia.
The U.S. forces engaged Felice Beato as official photographer for the intervention. Beato was living in Yokohama, Japan at the time, and already was one of the most famous photographers in the world. Together with his assistant, Mr. H. Woollett, he took graphic pictures of the fighting at the Kanghwa beach area. Some of his photos are currently illustrated in KOREA: Caught in Time by Terry Bennett (Reading, UK: Garnet Publishing, 1997)