In 1965, the First Infantry Division was selected to be the first division to deploy to Vietnam. The first unit to go from the Big Red One was the 2nd Brigade. Advanced parties landed at Qui Nhon on June 23, 1965. For nearly five years, the First Infantry Division soldiers battled against an aggressive enemy. The enemy made expert use of the dense jungles and inaccessible countryside. The use of helicopters was one of the best means of countering the jungle and the lack of roads. The experience gained in resupply operations, medical evacuation and the tactics of the air mobile assault has been used in developing basic doctrine in these areas. The First Infantry Division returned to Fort Riley in April 1970. Over 3,000 soldiers of the Big Red One died in action. Eleven Medals of Honor winners were added to the rolls.