"Today your nation finally acknowledges and fully honors your father's bravery," Obama said told the three sons of Richard L. "Dick' Etchberger at an awards ceremony in the East Room of the White House.
"Even though it's been 42 years, it's never too late to do the right thing," Obama said.
One of the sons said afterward that his father would have been humbled to receive the nation's highest military honor.
"He would be here just saying 'I was doing my job up there,"' Richard Etchberger told reporters.
A native of Hamburg, Pa., Etchberger was an electronics expert without formal combat training in March 1968 when he single-handedly kept the North Vietnamese enemy at bay while helping evacuate wounded comrades from their radar station on a remote Laotian mountain after coming under attack.
The next morning, Etchberger managed to get three wounded comrades into rescue slings and on their way to safety. But Etchberger was fatally wounded after enemy ground fire struck the helicopter attempting to lift him to safety.
Etchberger's mission was top secret and for years his children had been in the dark about it. Ritchard Etchberger, the son, said they were told only that he had died in a helicopter crash.