我查了下英文资料： 史密斯先遣部队400(500?)人7月5号与朝鲜坦克和陆军交火， 被打败；

7月下旬，美国24步兵师, 实际人数8660人, 被朝鲜军队打退；

八-九月, 联军与南韩军队组成140英里防御线, 六个星期, 成功的抵抗北朝鲜军队占领整个半岛, 双方死伤惨重, 被称为朝战最血腥的战役, 美国人称它为韩战的转折点。

• July 5, 1950: Task Force Smith (approx. 400 men) fought the first combat engagement at Osan.
• Late July 1950: The 24th Infantry Division, which had roughly 16,000 men on paper, was in Korea, but severely depleted, with only about 8,660 men accounted for by the end of July.
• Prior to Inchon: By the time Operation Chromite was launched in mid-September, the U.S. had managed to bolster its forces in the Pusan Perimeter, but for most of July and August, the American presence was severely understaffed and in a constant state of retreat. The Pusan Perimeter (Aug–Sept 1950) was a 140-mile, U.S.-led defensive line in southeastern Korea