A young South Vietnamese woman covers her mouth as she stares into a mass grave where victims of a reported Viet Cong massacre were being exhumed near Dien Bai village, east of Hue, in April of 1969. The woman's husband, father, and brother had been missing since the Tet Offensive, and were feared to be among those killed by Communist forces. #

U.S. air policemen take cover and leave their jeep as they come under sniper fire near Da Nang Airbase in Vietnam on January 30, 1968, after it was hit by a rocket barrage. Flares light up the Da Nang area to make it easier to spot infiltrating guerrillas. #

The flag of the Republic of Vietnam flies atop a tower of the main fortified structure in the old citadel as a jeep crosses a bridge over a moat in Hue during the Tet Offensive, February 1968. #

U.S. Marines and Vietnamese troops move through the grounds of the Imperial Palace in the old citadel area of Hue, Vietnam, on February 26, 1968, after seizing it from Communist hands. The heavy damage was the result of the artillery, air, and mortar pounding the area received for 25 days while the Viet Cong/NVA held the area. #

With dead U.S. soldiers in the foreground, U.S. military police take cover behind a wall at the entrance to the U.S. Consulate in Saigon on the first day of the Tet Offensive, January 31, 1968. Viet Cong guerrillas had invaded the grounds of the U.S. embassy compound in the earliest hours of the coordinated Communist offensive. #

South Vietnamese combat police advance toward a burning building in northeastern Saigon on February 19, 1968, as they battle Viet Cong forces who had occupied several city blocks in the area. #

A Viet Cong prisoner sits next to corpses of 11 of his slain fellow guerrillas after a street fight in Saigon-Cholon on February 11, 1968. In the background are Vietnamese Marines that defeated a Viet Cong platoon holed up in the residential area. The prisoner was later taken out for interrogation. #

The South Vietnamese General Nguyen Ngoc Loan, chief of the national police, fires his pistol into the head of suspected Viet Cong officer Nguyen Van Lem (also known as Bay Lop) on a Saigon street on February 1, 1968, early in the Tet Offensive. Lem was suspected of commanding a death squad which had targeted South Vietnamese police officers that day. The fame of this photo led to a life of infamy for Nguyen Ngoc Loan, who quietly moved to the United States in 1975, opening a pizza shop in Virginia. #

Assault boats in the Mobile Riverine Force of the U.S. 9th Infantry Division glide along the My Tho River, an arm of the Mekong Delta near Dong Tam, 35 miles southwest of Saigon, on March 15, 1968. #

Marine Lance Corporal Roland Ball of Tacoma, Washington, wearing his flak vest, starts the day off with a shave in a trench at the Khe Sanh Base in Vietnam on March 5, 1968, which was surrounded by North Vietnamese regulars. Ball uses a helmet as a sink and a rear-view mirror taken from a military vehicle. #

The bodies of U.S. Marines lie half buried on Hill 689, about two-and-a-half miles west of Khe Sanh, in April of 1968. Fellow Marines stand guard in the background after battling entrenched North Vietnamese troops for the hill. #

As fellow troopers aid wounded comrades, the first sergeant of A Company, 101st Airborne Division, guides a medevac helicopter through the jungle foliage to pick up casualties suffered during a five-day patrol near Hue, in April of 1968. #

Smoke rises from the southwestern part of Saigon on May 7, 1968, as residents stream across the bridge leaving into the capital to escape heavy fighting between the Viet Cong and South Vietnamese soldiers. #

U.S. President Lyndon B. Johnson listens to a tape recording from his son-in-law Captain Charles Robb at the White House on July 31, 1968. Robb was a U.S. Marine Corps company commander in Vietnam at the time. Robb was later awarded the Bronze Star and, after returning home, became governor of Virginia in 1982, and later a senator for the same state. #

Two napalm drops explode just outside Katum, a U.S. Special Forces camp about 60 miles northwest of Saigon on August 28, 1968. The napalm was used when Viet Cong attacked the camp. #

A U.S Marine with several days of beard growth sits in a helicopter after being picked up from the landing zone near Con Thein on the southern edge of the demilitarized zone in South Vietnam on July 18, 1968. His unit had just been relieved of duty after patrolling the region around the DMZ. #

Flying 100 feet above the jungle hills west of Hue, five bulky C-123 "providers" cut loose a spray of chemical defoliant on August 14, 1968. The planes are flown by U.S. air force crews who have nicknamed themselves the "ranch hands." The aircraft are specially equipped with huge 1,000-gallon tanks holding 11,000 pounds of herbicide. U.S. planes dropped millions gallons of chemical defoliant on Vietnam over the course of the war. #

Marines prepare their 105-mm Howitzers for action at the end of a day in which this dense jungle area west of Hue was chopped down and molded into a fire-support base for a sweep of the area on February 18, 1969. Troops used explosives and earth-moving equipment to carve out the gun pits and bunkers which by nightfall became a fire-support base. #

A Cobra helicopter gunship pulls out of a rocket and strafing attack on a Viet Cong position near Cao Lanh in the Mekong Delta on January 22, 1969. Large craters caused by air and artillery strikes brought in on the area can be seen near the white explosion. #

FBI agents carry Vietnam War draft resister Robert Whittington Eaton, 25, from a dwelling in Philadelphia on April 17, 1969, where Eaton had chained himself to 13 young men and women. The agent leading the way pushed one of the group who tried to block path to the sidewalk. At least six young persons were taken away with Easton. #

A trooper of the 101st Airborne Division attempts to save the life of a buddy at Dong Ap Bia Mountain, near South Vietnam's A Shau Valley on May 19, 1969. The man was seriously wounded in the last of repeated attempts by U.S. forces to capture enemy positions there. #

A GI gets a closeup photo as President Nixon meets with troops of the 1st Infantry Division at Di An, 12 miles northeast of Saigon, on his eighth visit to South Vietnam and his first as president, on July 30, 1969. #

Marine Lance Corporal David L. Cruz tunes into the latest news on the Apollo moon shot on a helmet-mounted transistor radio while standing guard at Da Nang's Marble Mountain, on July 17, 1969. In background is a tall Buddhist figure found in many limestone caves of the mountain. #

Demonstrators listen to a performer in Central Park on Moratorium Day, October 15, 1969. Moratorium Day was a mass demonstration and teach-in staged across the United States, in protest against continued American involvement in Vietnam. #

Three shirtless U.S. soldiers advance through the Mimot rubber plantation in the Fishhook region of Cambodia, on May 4, 1970, taking aim at a fleeing suspect. The rubber plantation, one of the largest in Indochina, had been in operation until just a few days earlier. #

A GI of the U.S. 199th light infantry brigade walks through bodies laid out just outside the barbed wire perimeter of U.S. firebase crown in Cambodia on May 14, 1970. Fifty North Vietnamese were killed and only four Americans wounded when the North Vietnamese, presumably thinking the firebase already abandoned, walked into an ambush by the American defenders. #

Vietnamese and Cambodian refugees crowd a U.S. helicopter which evacuated them from immediate combat zone of the U.S.-Vietnamese incursion into Cambodia on May 5, 1970. They were taken to a refugee reception center at the Katum Special Forces camp in South Vietnam, six miles from the Cambodian border. #

The Ohio National Guard moves in on rioting students at Kent State University in Kent, Ohio, on May 4, 1970. Four persons were killed and eleven wounded when National Guardsmen opened fire. #

Fourteen-year-old Mary Ann Vecchio screams over the body of 20-year-old Kent State student Jeffrey Miller after he was shot by the Ohio National Guard during a protest against the U.S. invasion of Cambodia during the Vietnam War on May 4, 1970. #

In this photo taken from video, soldiers in fire-support base Aries, a small clearing in the jungles of War Zone D, 50 miles from Saigon, smoke marijuana using the barrel of a shotgun they nicknamed "Ralph," to get high on November 13, 1970. #

U.S. artillerymen relax under a crudely made peace flag at the Laotian border in 1971. The gunners were giving covering fire for South Vietnamese troops operating inside Laos. #

South Vietnamese Marines check the bodies of dead soldiers for cigarettes near My Chanh, new government defense line 20 miles north of Hue, on May 5, 1972. The soldiers were killed during fighting when Quang Tri City was abandoned. #

Bombs with a mixture of napalm and white phosphorus jelly dropped by Vietnamese AF Skyraider bombers explode across Route 1, amid homes and in front of the Cao Dai Temple in the outskirts of Trang Bang, on June 8, 1972. In the foreground are Vietnamese soldiers and news and cameramen from various international news organizations who watch the scene. #

South Vietnamese forces follow after terrified children, including 9-year-old Kim Phuc, center, as they run down Route 1 near Trang Bang after an aerial napalm attack on suspected Viet Cong hiding places, on June 8, 1972. A South Vietnamese plane accidentally dropped its flaming napalm on South Vietnamese troops and civilians. The terrified girl had ripped off her burning clothes while fleeing. The children from left to right are: Phan Thanh Tam, younger brother of Kim Phuc, who lost an eye, Phan Thanh Phouc, youngest brother of Kim Phuc, Kim Phuc, and Kim's cousins Ho Van Bon and Ho Thi Ting. Behind them are soldiers of the Vietnam Army 25th Division. #

A beheaded statue of an American soldier stands next to a bombed-out theater near the district town of Cu Chi, northwest of Saigon, on December 13, 1972. The statue was placed by troops of the U.S. 25th Infantry Division before they were withdrawn from Vietnam two years earlier. Its head was lost in the explosion that destroyed the theater in background. #

A South Vietnamese widow cries as a bell at a Saigon Buddhist pagoda tolls the ceasefire at 8 a.m., on Sunday, January 28, 1973, Saigon time. The United States had begun drastically reducing forces in the country, and, following the Paris Peace Accords of 1973, the last remaining American troops withdrew in March of 1973. #

A bon voyage banner stretches overhead in Da Nang, South Vietnam, as soldiers march down a street following a farewell ceremony for some of the last U.S. troops in the country's northern military region, on March 26, 1973. #

The released prisoner of war Lieutenant Colonel Robert L. Stirm is greeted by his family at Travis Air Force Base in Fairfield, California, as he returns home from the Vietnam War, March 17, 1973. In the lead is Stirm's daughter Lori, 15; followed by son Robert, 14; daughter Cynthia, 11; wife Loretta and son Roger, 12. This famous photo, also called "Burst of Joy," won a Pulitzer Prize in 1974. The happy scene depicted here was not to last, however. Stirm, after spending five years in captivity, had received a "Dear John" letter from his wife Loretta, just three days before returning home. They divorced in 1974. #

A refugee clutches her baby as a government helicopter gunship carries them away near Tuy Hoa, 235 miles northeast of Saigon on March 22, 1975. They were among thousands fleeing from recent Communist advances. With U.S. forces out of the country, North Vietnamese troops tested South Vietnamese defenses (and the willingness of the U.S. to return to the fight) starting in 1974, and began capturing territory. #

The Fall of Saigon. Fleeing advancing North Vietnamese forces, mobs of South Vietnamese civilians scale the 14-foot wall of the U.S. embassy in Saigon, April 29, 1975, trying to reach evacuation helicopters as the last Americans departed from Vietnam. #

A cluster of South Vietnamese marines, some of whom unable to swim, hold onto inner tubes and empty plastic containers as buddies throw them a line to pull them aboard a navy LST off China Beach at Danang as they fled the port city in April of 1975. #

A North Vietnamese tank rolls through the gate of the Presidential Palace in Saigon, April 30, 1975, signifying the fall of South Vietnam. The Socialist Republic of Vietnam was formed in 1976, uniting North and South. Millions of South Vietnamese were sent to reeducation camps, millions more fled the country on their own, leading to the Indochina refugee crisis that lasted another quarter of a century. #