19-year-old Pfc. John Ross of Port Charlotte, Fla. with his M-60 machine-gun. He fought with the 173rd Airborne Brigade in Vietnam in 1967-68.

A young Marine Private waits on the beach during the Marine landing, August 3, 1965.

18-year-old soldier in Vietnam, 1963.

Pvt. Jim Mazy of Englewood, Fla. pictured as an 18-year-old Marine who took part in the first major battle in Vietnam involving American forces called “Operation Starlite” on Aug. 18, 1965.

Airman William Pook, shown here in 1972, served in the Vietnam War while stationed at Tahkli Royal Thai Air Force Base, Thailand. Pook was 18 years old when he was assigned to the 49th Tactical Fighter Wing, and retired as a Master Sergeant at Langley AFB, Va., on Sept. 23, 2011, after 40 years in the Air Force.

18-year-old soldier, Vietnam.

Iconic photograph shot June 18, 1965, by the late Pulitzer Prize winning photographer Horst Faas, captioned as an unidentified American soldier of the 173rd Airborne Brigade. Fran Chaffin Morrison claims it is her late husband, Larry Wayne Chaffin, who served with that brigade in Vietnam for exactly one year beginning in May 1965.

Steve Cameron left his family farm in New Milford, Ill., and joined the Marines in June 1965. He was 20 years old, and the Vietnam War was raging a half a world away. If he didn’t enlist, he knew he’d be drafted. “If your country needed you, there were no excuses, no cowardice and no second thoughts in serving your country,” he said.

Milton Lee Olive, III. Private First Class Olive and four other soldiers were moving through the jungle together when a grenade was thrown into their midst. Private First Class Olive saw the grenade, and then saved the lives of his fellow soldiers at the sacrifice of his by grabbing the grenade in his hand and falling on it to absorb the blast with his body. Through his bravery, unhesitating actions, and complete disregard for his safety, he prevented additional loss of life or injury to the members of his platoon.

A young Paratrooper with a mud-smeared face stares into the jungle in Vietnam on July 14, 1966, after fire fight with Viet Cong patrol in the morning. He is a member of C Company, 2nd Battalion, 173rd Airborne Brigade.

John Dittmann, 1967. US soldier of the 2nd Battalion, 14th Infantry Regiment, Ho Bo, Vietnam.

An American soldier after the capture of Hill 471, near the northern border of Khe Sanh, Vietnam, April 1968.

A GI smokes two cigarettes in Vietnam.

Photograph of Private First Class Russell R. Widdifield in Vietnam, 1969.

A moved US soldier from the 9th Division at Tan An, Vietnam 1968. He has received three Purple Heart decorations.

Special Forces Green Beret Master Sgt. John Hartley Robertson (far left) 1968 - the year he was declared missing after his helicopter crashed.

Specialist Denny Kirkham patrols the hilltops in Vietnam in 1970. Kirkham, only 18-years-old when drafted, earned a Bronze Star for his duties as a radio operator during the Battle of Fire Support Base Ripcord in the A. Shau Valley, the only battle lost by the 101st Airborne Division in Vietnam.

196th Light Infantry Brigade arrives in Vietnam, 1966. A soldier is given a flower by a Vietnamese girl.

Undated photo of unidentified U.S. Soldier in Vietnam. When the United States sent ground troops into Vietnam in 1964, one out of every seven (about 14 percent) of those soldiers was African American.

A 20-year-old Stephen Manthei, right, and fellow soldier Bob Tarbuck, left, prepare for the Battle of Ripcord, during which their platoon was attacked, killing everyone but the two of them.

U.S. Special Forces Soldier, Vietnam.

Sgt. Alex Adams of Morgantown, W. Va. (with the telephone) and Pfc. Ron Hooper of Wichita Falls, Texas (looking through the binoculars) keep lookout from the top of Marble Mountain for any signs of trouble around the Da Nang airbase, November 1st, 1965.