The Eighth Army now consisted of the U. S. I Corps (IX Corps did not become operational until 23 September) and the ROK I and II Corps. General Walker’s command was already on the way to becoming the most cosmopolitan army in which Americans have ever served. Contingents of British ground forces had reached the front; and before the end of the year, 40 countries of the United Nations would have offered assistance, either military or economic, to the fight against Communism. Most of this aid had not yet materialized on 16 September, but the Eighth Army had overcome its disadvantage in numbers of trained troops, thanks to NKPA losses, when it jumped off all along the line in southeast Korea. In the north the 1st Cavalry Division, 24th Infantry Division, ROK 1st Division, and British 27th Brigade launched a determined attack along the Taegu-Waegwon axis to win a bridgehead across the Naktong. It was nip-and-tuck for the first three days, and not until the 19th did the UN forces fight their way across the river against the last-ditch opposition of the 1st, 3d, 10th, and 13th NKPA Divisions.[259] [259] Almond, _UN Mil Ops_, 13. Still farther north, the enemy relinquished little ground until the 18th. On that date the ROK 3d Division recaptured the east coast port of Pohang-dong, which the invaders had taken in their drive during the first week of September. In the south, the U. S. 2d and 25th Infantry Divisions and attached ROK units were held up for three days by the NKPA 6th and 7th Divisions. The deadlock lasted until 19 September, when the enemy fell back in the Masan area along the southern coast.[260] [260] _Ibid._ Major Joseph H. Reinburg’s VMF(N)-513, operating out of its Itazuke base, played a conspicuous role in the first days of Walker’s offensive. Although specialists in night-fighting, the Marine pilots flew 15 daylight close support missions for Army units from 17 to 19 September. Enemy troops, tanks, vehicles, and artillery were scored during every strike, as the planes ranged the entire extent of the Pusan Perimeter.[261] [261] 1st MAW _SAR_, Annex Item, VMF(N)-513 rpt. _Division CP Displaces to Oeoso-ri_ So much progress had been made by this date on the X Corps front that General Smith displaced the 1st Marine Division CP from the eastern outskirts of Inchon to Oeoso-ri, about a mile and a half southeast of Kimpo Airfield. This forward location was selected by General Craig with a view to preliminary Division planning for the crossing of the Han, which would entail a reshuffling of units.