Upon the outbreak of the Korean War, "Fort Marion" sailed for action 12 July 1950, and arrived at Pusan with Marines and their equipment 2 August. For the next month, she ferried troops from Kobe to Yokosuka for further routing onward to Korea. On 12 September, at Pusan, "Fort Marion" embarked men of the 3rd Battalion, 5th Marines and three LSUs, carrying ten tanks, for the invasion of Inchon.