Striking sanitation workers in Memphis, Tenn., march on Friday, March 29, 1968 — one day after a protest led by the Rev. Martin Luther King Jr. littered streets with bricks and shattered glass. About 200 youths had broken windows and looted stores.

AP / BARNEY SELLERS

PROVIDENCE — It was the year all of the convulsions of the tempestuous 1960s melded to excite, polarize, sadden, anger and scare Americans.

1968 was a blur of the Vietnam War, the assassinations of Martin Luther King Jr. and Robert F. Kennedy, the abdication of President Lyndon B. Johnson, protests by women and blacks, racial conflict, youth rebellion, blood in the streets at the Democratic National Convention in Chicago, the Soviet invasion of Czechoslovakia, the first manned voyages of the Apollo space program, and a conservative backlash that would vault Richard Nixon into the White House.

Forty years ago, college campuses erupted in protest, a generation gap emerged as young people questioned society’s rules and a once disciplined social order crumbled under such taboo-shattering indulgences as LSD, pot, unisex hairstyles, open cohabitation and the demands of women for equality.

It was a time when everybody had to be heard — especially those who felt they had never had a real voice in American society. Leftists and rightists, yippies and hippies, squares and beats, Black Panthers and white supremacists, environmentalists and industrialists, women’s libbers and defenders of the status quo all vied for space in a new media world dominated by television.

Music was openly rebellious, focusing on drugs, war and sex. A British hit by the rock group Small Faces — “Itchycoo Park” — reached number 16 on the U.S. music charts with such lyrics as “What will we do there? We’ll get high.”

Rhode Islanders struggled with desegregation of the Providence schools, a series of strikes by organized labor at local industries and the telephone company, the movement of the capital city’s downtown retail landmarks to suburban Warwick, a sharp-edged political battle over taxes that resulted in the longest General Assembly session in history and the defeat of incumbent Republican Gov. John H. Chafee, who would later win election to the U.S. Senate.

It wasn’t all doom, gloom and upheaval. The war-fueled economy blossomed; the U.S. jobless rate was 3.3 percent, the lowest since 1953. Just about any man who wanted a job had one; the unemployment rate for adult men was 2 percent. Americans zoomed around in souped-up Detroit iron — Chevrolet Camaros, Pontiac GTOs — guzzling cheap, plentiful gasoline.

Thirty-five percent of Americans smoked. The advertising icon of the era was that macho cowboy, the Marlboro Man.

This Last Fine Time wouldn’t last. The Vietnam War ushered in inflation. By the early 1970s there were oil price shocks and energy shortages. The blue skies of the 1960s had given way to an era of limits that lingers today.

The year began innocently enough with the sale of the Beatles Magical Mystery Tour album. But things quickly turned sour in late January as South Vietnam, the U.S. ally, was overrun by North Vietnamese troops and guerrilla soldiers from the Viet Cong in the Tet offensive.

In later years, military historians would debate whether the Tet offensive was really a victory for the North Vietnam troops and the Viet Cong, who lost many, many more soldiers than the United States, but at the time the first televised war in U.S. history beamed an incredible story into living rooms every evening. The nation was jolted.

Americans had never lost a major war, but now Viet Cong peasants running around in what looked like pajamas and flip-flops made from used tires appeared to be battling the strongest military force in the world to a stalemate. When Walter Cronkite — the CBS television anchor, who was known as one of the nation’s most trusted men — heard about the wave of the Tet attacks, he said: “What the hell is going on? I thought we were winning this war.”

The attacks generated momentum for a protest movement that until Tet had been largely confined to students on college campuses, liberal activists and some lawmakers in Washington. Now the anti-war movement spilled into the mainstream as Minnesota Sen. Eugene McCarthy challenged President Johnson for the Democratic presidential nomination.

Little known outside the nation’s capital and in his native Minnesota, the cerebral McCarthy, a poet and onetime college professor, seemed an improbable presidential aspirant. But when anti-war liberals failed to persuade Robert Kennedy to become the political vessel of the Vietnam movement, McCarthy announced his candidacy.

As the anti-war movement went mainstream, McCarthy picked up support among Democratic Party activists and rank-and-file voters who had grown tired of the war, in which 500 U.S. soldiers were now losing their lives each week. In the New Hampshire presidential primary on March 12, McCarthy captured 42 percent of the vote against Johnson — an astounding showing against a powerful incumbent.

ON MARCH 31, Johnson, who had hungered for the White House since his impoverished youth in rural Texas, surprised the world. In a televised speech, LBJ reversed course in Vietnam, announcing that he was halting the bombing of North Vietnam and calling for peace talks.

At the end of the speech, Johnson dropped out of the race for reelection. “I shall not seek, and I will not accept the nomination of my party for another term as your president.”

Johnson’s peace initiative and departure from the campaign lifted the country’s spirits. The New York Stock Exchange soared, public opinion surveys showed a reversal in the president’s negative ratings and media commentators hailed his statesmanship.

The euphoria lasted four days.

On April 4, civil rights leader Martin Luther King Jr., was murdered in Memphis as he readied a march in support of striking garbage workers. King was the leader of the movement that had ended Jim Crow segregation in the South and brought the right to vote to blacks who had been barred from exercising this bedrock democratic principle.

A Baptist preacher, inspiring orator and world-renowned peace and justice advocate, King held fast to his principles of nonviolence. “To the end, he resisted incitements to violence, cynicism, and tribal retreat,” wrote historian Taylor Branch. “He grasped freedom seen and unseen, rooted in ecumenical faith, sustaining patriotism to brighten the heritage of his country for all people.”

The black civil rights movement would become the model for other segments of U.S. society who believed they were not treated fairly by the political and economic status quo. “It was an incredibly powerful movement … no other movement did as much to raise rights consciousness in our society, for women, for the poor, for gays, for native Americans, the handicapped, as civil rights,” says James T. Patterson, a retired Brown University history professor and a leading 20th-century historian.

After King’s murder, riots broke out in more than 100 cities across the country. Rhode Island was spared the violent racial disturbances, but there were serious conflicts over segregated housing and schools in Providence.

To avoid school integration in the capital city, many white parents had begun in September 1967 to pull their children from public schools.

But the strongest opposition to the city’s integration plan came from the black community. Black parents were upset because the city called for busing only black children out of their neighborhoods to predominately white schools. No white students were to be sent to schools in predominately black neighborhoods.

Black parents protested in fall 1967 by taking their children out of white schools and staging a 36-hour sit-in at the School Department. In January 1968, they won a compromise when the School Department created a “model school” at Flynn School in a mostly black section of South Providence. White students enrolled voluntarily and Flynn opened with a mix of 70 percent white and 30 percent black students.

Providence schools today have fewer non-Hispanic white students than ever before. In 1968, minority students, almost all of them black, made up about 30 percent of Providence students. Four decades later, roughly 88 percent of city public school students are minorities, with the largest single group Hispanic. Twelve percent are white.

Eight weeks after King’s murder, the evening Robert Kennedy claimed victory on June 5 in the California presidential primary, the New York State senator was cut down by an assassin’s bullet. Once again, the nation mourned. Another Kennedy widow hovered over a casket, another grim trip to Arlington National Cemetery.

CULTURAL and social issues burst into the nation’s agenda throughout the year.

In July, Pope Paul VI issued his encyclical condemning artificial birth control just as the sexual revolution was enveloping the United States. Women’s rights activists were pushing to relax state laws banning abortions and protested the Miss America contest for promoting a superficial, sexist image.

By 1968, the women’s movement was already having an impact; Shirley Chisholm, from New York City who famously said that her gender was a higher hurdle than her race, became the first black woman elected to the U.S. House of Representatives.

In August, the streets of Chicago were the scene of bloody protests during the Democratic National Convention that spurned McCarthy, the anti-war candidate, and nominated LBJ’s vice president, Hubert Humphrey, of Minnesota, as the standard bearer of a party bitterly divided over Vietnam.

Republicans chose Nixon, who had lost the 1960 election to John Kennedy and, in 1962, met defeat in an election for governor of his home state, California. George Wallace, the segregationist Alabama governor, ran on a third-party ticket and drained votes from Humphrey in the North and Nixon in the South. Nixon eked out a win over Humphrey.

The year ended on a more hopeful note. On Christmas Eve, the Apollo 8 astronauts were headed back to Earth after circling the moon 10 times. The photos of the moon transmitted back home by the astronauts were greeted with awe by earthling Americans who had endured a tragic and historic year.

Historians and pundits still argue over the meaning of the 1960s and the pivotal year of 1968.

“The fact is the ’60s are still with us and will be for the imaginable future,” wrote historian Rick Perlstein this year.

smackay@projo.com