In the rainy predawn darkness of July 5, 1950, two US Army rifles companies reinforced by six howitzers—about four hundred men in all—dug in on a saddle-shaped hill straddling a highway just north of Osan, South Korea. The hill was an outstanding north-facing defensive position: to this day, a soldier on that hill can see eight miles of the crucial strategic road that bends northwest, towards the city of Suwon, today known as the home of Samsung, but in 1950 famous for the ancient walls of Hwaesong Fortress that surround it. Two weeks before, communist North Korea, with Soviet support, had crossed the 38th parallel and invaded America’s partner South Korea. The American soldiers entrenched on the hill, called Task Force Smith after their commander, Lt. Col. Charles B. Smith, were about to become the first American soldiers to see ground combat in the Korean War.