The 1950s are remembered as a time of conformity.

The war was over as was the Depression. We could focus on our wants, not just our needs.

The Cold War meant we had a common enemy in Communism. Those who showed an inclination to be pro-Soviet were condemned.

People generally abided by commonly accepted rules of behavior. That era is memorialized in books like Sloan Wilson’s “The Man in the Grey Flannel Suit” and “The Organization Man” by William Whyte, by TV shows such as “Father Knows Best” and “Leave it to Beaver” and movies like “Mr. Blandings builds his Dream House,” with all-American Hollywood stars: Gary Grant and Myrna Loy.

Etiquette and civility were de rigueur. It was a period protected by a political system that reflected mainstream America. Today, many idealize those years and look back on that time with longing fondness.

But conformity hid an uglier America that consisted of poverty, racism, sexism and alienation. Television was in its infancy. If one lived in Fairfield County, one had little concept of the way people lived in Appalachia or Watts. If one was white and lived in the Pacific Northwest, one had no contact with those in Little Rock or Harlem.

Class differences were distinct. “People,” as the saying then went, “knew their place.” Young women were expected to be proper. If an unmarried teenage girl became pregnant, she was whisked out of sight until an illegal abortion could be performed or the newborn baby given up for adoption.

Conformity means little room for differences in opinions. The McCarthy hearings, which dominated the early post-War years, showed the harm done when dissent is censured. The nastiness of Sen. Joseph McCarthy was allowed to percolate until, finally, in 1954, Army attorney Joseph Welch rhetorically asked the Senator, “Have you no sense of decency?”

Even earlier there had been challenges. “Catcher in the Rye,” J.D. Salinger’s coming-of-age novel, was published in July 1951, and a year later Ralph Ellison wrote “Invisible Man.” Both were considered blasphemous. The 1955 movie “Rebel Without a Cause” was thought of as scandalous, because the main characters came from “good families.”

Nevertheless, the conformity of the 1950s came to an end – at first gradually and then with accelerating speed, culminating in the late 1960s with campus protests, civil rights marches and anti-war demonstrations.

In the years that followed, campuses once again nurtured those who dared be different. Opposition and diversity of opinions became common.

But that period of relative intellectual freedom began to erode; as political correctness invaded campuses, conformity returned, but in a different guise. Today, it evidences itself through politically correctness.

It is seen most notably in our universities, but also in the speech of the political Left. In the 1950s, it was the “establishment” — the business and banking communities, the country club set, Republicans.

This time conformists reside in universities, places in which those of differing persuasions are excluded. They are the California environmentalists, West Side residents and, again, the country club set, but now limited to places like Connecticut.

This time it is Democrats – defenders of the liberal Left – who demand conformance to their policies.

Conformity leads to contempt and intolerance. In its worst form, it manifests itself among Islamic extremists who rape, brutalize and kill disbelievers. In a lesser way, but insidious in its subtlety and of more immediacy to us, it is rampant on American campuses.

Political correctness is well-intentioned. It is a desire to be inoffensive to those singled out as different — victims, if you will, of the alleged barbaric behavior of society. But it implies superior intellect. It is based on a “group-think” mentality. It caters to the supercilious. It will be ubiquitous during the Paris climate talks this fall. It reflects an arrogance that demands allegiance.

Walter Williams, in a column last Tuesday, wrote of a visit to Oberlin College by Christina Hoff Sommers, an avowed feminist, former philosophy professor and scholar with the American Enterprise Institute. Because her research did not accord with accepted views, trigger warnings were issued.

Her presence on campus, it was alleged, was “a form of violence.” Thirty students, along with the college “therapy” dog, retired to a safe room with soft music, crayons and coloring books! (The annual cost to attend Oberlin in the 2014/15 year was $63,696. Is this what parents expect in return?)

Keep in mind the same folks that are protective of Oberlin’s fragile female students are the ones pushing women to be allowed to serve in combat. Should we laugh or cry?

In the past few years, college administrators have retreated to bunkhouses, intimidating those who would challenge the status quo. In the 1950s, it was the “beat” generation — the artistic world of musicians, artists, writers and poets — that challenged authority. This time, students, administrators and most teachers are on the same side.

It was the Tea Party that took up the cudgel to defend the right to speak against the nabobs of normalcy that are found on politically correct campuses and that exist in the cronyism that is a consequence of big government, big business and big labor. This threat of an ideological and imperious conformance reflects a growing dissatisfaction with Washington and helps explain the appeal of Donald Trump and Bernie Sanders.

Society is at risk whenever conformity becomes pervasive. It conjures memories of Hitler’s storm troopers, or China’s Red Guard. It explains our experience with McCarthyism sixty-five years ago and the anti-intellectualism prevalent on campuses today. Colleges and universities are the laboratories that prepare the next generation of leaders. To the extent they all march to the same drummer, it portends political and social conformity in the years ahead.

Strong leadership can calm turbulent waters; there is comfort in knowing that one is being looked after — think of “Julia” and the “pajama boy.” But that is the argument every despot has always used. It suggests, as Thomas Jefferson once wrote, “a government of wolves over sheep.”

Freedom is not easy and quelling dissension can seem the proper response. But doing so leads inexorably toward authoritarianism. Leadership and political ideas should always be challenged. We are better off with a querulous Congress than one mired in unity.

There is no perfect society or political philosophy. Life is about the quest, not the destination. We should welcome those who question, not condemn them as ignoramuses. Conformity is the enemy of liberty.