Forty years ago, America’s cultural icons expressed the frustration of the American people with the failure of then-President Lyndon Johnson to end this country’s undeclared war in Vietnam by boldly demanding peace.

The most respected newsman in the nation, CBS anchorman Walter Cronkite, explained to a national television audience after the Tet Offensive that the war had gone horribly awry.

Singer Johnny Cash, whose music and style had made him a hero of blue-collar Americans, described himself as “a dove with claws” and began singing the anti-war song “Last Night I Had the Strangest Dream.”

The Smothers Brothers variety show was censored when it attempted to air a segment featuring Harry Belafonte singing in front of images of student protesters clashing with the police. CBS executives reportedly feared that the implicit anti-war message would offend President Johnson and his aides.

But the most direct and powerful anti-war statement of the period was delivered by singer Eartha Kitt, then at the height of her celebrity.

Kitt, the sultry singer of hits such as “Santa Baby” who died at age 81 on Christmas Day, was in 1968 an internationally acclaimed music star who had begun making major stage and screen appearances. So it came as no great surprise when she was invited to a White House luncheon hosted by Lady Bird Johnson.

But the first lady was surprised when she asked Kitt about the Vietnam War.

“You send the best of this country off to be shot and maimed,” the singer told the first lady and the 50 other women at the luncheon. “They rebel in the street. They don’t want to go to school because they’re going to be snatched off from their mothers to be shot in Vietnam.”

The first lady reportedly burst into tears.

The president was furious.

Kitt was blacklisted. She was investigated by the FBI and CIA, and ended up on the “Enemies List” of Johnson’s successor, Richard Nixon.

Kitt spent the next decade performing mostly in Europe until, in 1978 — after a triumphal return to Broadway to perform in the musical “Timbuktu!” — she was invited back to the White House by the great healing executive of the post-war era, Jimmy Carter.

Years later, Kitt would recall her White House visit in an interview with Esquire magazine, saying “The thing that hurts, that became anger, was when I realized that if you tell the truth — in a country that says you’re entitled to tell the truth — you get your face slapped and you get put out of work.”

It was a painful lesson.

But we remember Kitt today as one of those remarkable Americans who was patriotic enough to speak truth to power. And she spoke in such a remarkable voice that it will linger far longer in our memory than those of the foolish politicians and misguided media moguls who were wrong about Vietnam — and wrong about Eartha Kitt.