General MacArthur ordered Major General Hobart R. Gay, commander of the US 1st Cavalry Division, to plan the division's amphibious landing at Incheon

Against the rested and re-armed Pusan Perimeter defenders and their reinforcements, the KPA were undermanned and poorly supplied; unlike the UN forces, they lacked naval and air support. To relieve the Pusan Perimeter, General MacArthur recommended an amphibious landing at Incheon, near Seoul and well over 160 km (100 mi) behind the KPA lines. On 6 July, he ordered Major General Hobart R. Gay, commander of the US 1st Cavalry Division, to plan the division's amphibious landing at Incheon.