Battle of Ganghwa The Battle of Ganghwa was fought during the conflict between Korea and the United States in 1871 . In May , an expedition of five Asiatic Squadron warships set sail from Japan to Korea in order to establish trade relations , ensure the safety of shipwrecked sailors , and to find out what happened to the crew of the SS " General Sherman " . When American forces arrived in Korea , the originally peaceful mission turned into a battle when guns from a Korean fort suddenly opened fire on the Americans . The battle to capture Ganghwa Island ' s fort s was the largest engagement of the conflict . Background . The United States Navy expedition involved over 1 , 400 personnel , 542 sailors , 109 marines and six 12 - pounder howitzer s made up the landing party . Frigate USS " Colorado " , the sloops USS " Alaska " and USS " Benicia " and the gunboat s USS " Monocacy " , and USS " Palos " were assigned to the operation , all together mounting 85 guns under the command of Rear Admiral John Rodgers and Commander Winfield Scott Schley . Korean forces included the six Selee River Forts , of various sizes , and four shore batteries with over 300 men and dozens of artillery pieces . While negotiations were going on at Inchon , on June 1 , 1871 , USS " Palos " was engaged by one of the forts so the " Palos " and USS " Monocacy " returned fired and silenced it . Rear Admiral Rodgers demanded an apology but none came so nine days later , the expedition attacked in force . Battle . The battle began on June 10 , when the American squadron arrived of Point Du Conde and began bombarding the fort there . The shore party was landed by boats which immediately launched an attack on Fort Du Conde which was taken without serious resistance . Next , the Americans proceeded north a short distance where they captured Fort Monocacy , skirmishing with bodies of Korean troops along the way . After the fall of Fort Monocacy , the Americans rested for the night and became the first western military forces to camp on Korean soil . On June 11 , the main engagement occurred , the five warships began bombarding the four remaining forts while the shore party attacked from land . About 300 Koreans , armed with matchlock rifles , swords , and clubs held Fort McKee which was the heart of Korean defenses . One by one the Americans led by Lieutenant Hugh McKee climbed over the fort ' s walls . Fierce close quarters combat ensued but it lasted only fifteen minutes until the fort was secure . In the end , 243 Koreans were counted dead , twenty captured and a few wounded . Over forty cannons ranging from two to 24 - pounders were also taken and within the next few days the forts were dismantled , with the exception of Fort Palos , on the other side of Ganghwa Straits . Corporal Charles Brown captured a large sujagi , for this he received the Medal of Honor . Under heavy fire , Carpenter Cyrus Hayden planted the American flag on top of the Korean fort , an act which earned him the medal as well . Private James Dougherty personally shot and killed the Korean commander General Eo Jae - yeon , he was also awarded the Medal of Honor along with six others . Only three Americans were killed and ten were wounded , USS " Monocacy " grounded on rocks off Fort McKee during the battle , she was re - floated and sustained only slight damage . Though the battle was a victory for American forces , the Koreans refused to begin trading with the United States . It was not until 1882 when a trade treaty was finally signed .