A prominent plaque at the National Baseball Hall of Fame and Museum contains this familiar quotation from French-born historian Jacques Barzun:

"Whoever wants to know the heart and mind of America had better learn baseball."

Sadly, it's in a museum, surrounded by other relics, where Barzun's 1954 observation belongs.

The long-held notion that America is reflected in its onetime pastime is, in 2014, as passé as a slap-hitter. In fact, when it comes to baseball and the new national reality, the opposite is often true.

Take unions, for example. While the Major League Baseball Players Association is a Ruthian force, labor's power elsewhere in America is akin to Ben Revere's.

It's ironic that when the labor movement was at its peak in the 1950s - in 1954 nearly 35 percent of American workers were union members - baseball players remained as powerless as medieval serfs.

When Robin Roberts won 28 games and had a 2.59 ERA in 1952, the Phillies pitcher had to sell cardboard boxes in the offseason to support his family. That same year, Ralph Kiner won a seventh consecutive National League home-run title, and the Pittsburgh Pirates cut his salary by 25 percent.

By 1965, when Roberts recommended that the toothless MLBPA hire Marvin Miller as its director, the average baseball salary barely topped $14,000.

A half-century later the spike is on the other foot.

While in baseball the average player earns $3.4 million annually, elsewhere salaries are stagnating or in decline. As of 2013, only 11.3 percent of U.S. workers were union members, and the influence of labor, as well as public support for it, has slipped badly.

Millions now face the same peril and uncertainty that haunted generations of baseball players. Those with jobs have little or no bargaining power. Their salaries can be cut at any time. And, in an era when job security has become a meaningless phrase, so can they.

And yet, far from turning to unions for help, those who might be expected to benefit most from organized labor are often its fiercest opponents.

A recent Pew Research Center survey found that 42 percent of Americans had an unfavorable opinion of unions.

Much like those 1950s players, who were led to believe unionization would destroy their livelihood, these Americans have been persuaded to turn against their own self-interest.

Baseball, of course, isn't the steel industry. Its employees are pampered millionaires. Many, in fact, would argue that the MLBPA isn't a union at all, but rather an elite collection of uniquely talented and extremely wealthy people.

Miller, who died in 2012, always disagreed with that assessment.

"Any group of people working together to advance the interest of the group," he said, "is, under the terms of labor law, a union."

Miller was no thuggish union boss. He used the machinery of established labor law, and not extralegal measures, to transform his 90-pound weakling into a behemoth.

Players and owners negotiated a collective-bargaining agreement in 1968, the first in major professional sports. Two years later players earned the right to air their grievances before an impartial arbitrator. In 1973, their salary demands also became arbitration-eligible.

It was a revolution baseball's powers had long feared and fought against. And yet it was as bloodless as it was successful.

Yes, there were contentious stretches that resulted in several strikes and the cancellation of the 1994 World Series. But in the long run, a better, more financially secure game emerged.

Despite what owners had long been predicting, a strong union strengthened the sport. It wasn't just salaries that rose. So did attendance and all sorts of revenue streams, including several that neither the owners nor Miller could have imagined in 1965.

In fact, though, it remains the only major sport without a salary cap, the value of baseball's 30 franchises has grown as fast as players income.

According to a Forbes magazine evaluation, the New York Yankees are worth $2.5 billion, the Los Angeles Dodgers $2 billion, the Phillies $975 million. Even the Oakland A's, whose history of penury dates back a century to Connie Mack, are valued at $495 million, 54 percent more than in 2012.

Through the cooperation of owners and players, as the pie expanded, it continued to be fairly sliced. In the end, the game and the union got their just deserts.

There would seem to be lessons here that the American business community could learn and apply. And yet, for the past 30 years, it has been steaming rapidly in the opposite direction.

Next week, nonunionized fast-food workers in 150 U.S. cities, many earning minimum wage, plan to strike to accentuate their demands for higher pay. Some of their corporate employers, abetted by their political allies, will fight them and their union-organizing efforts.

Their dire warnings of shut-down franchises and job losses will sound strikingly familiar, like those empty threats that baseball's Lords of the Realm spewed for generations.

Perhaps, if both sides are genuinely interested in long-term peace and profits, they ought to be looking for another Miller.

The MLBPA is Miller's legacy. In shaping it into America's most successful union - and in the process reshaping baseball - he became one of the most significant figures in the sport's history.

Broadcaster Red Barber once said Miller's influence was matched only by that of Babe Ruth and Jackie Robinson.

And in his introduction to Miller's book, A Whole New Ball Game, revered stats guru Bill James wrote: "If baseball ever buys itself a mountain and starts carving faces on it, one of the first men to go up is sure to be Marvin Miller."

That might have been one of the few things about baseball that James got wrong.

The sport, after all, does have a Mount Rushmore. It's in Cooperstown, and it's called the Hall of Fame.

It's a place that has opened its doors to racists, drunks, misanthropes, wife-beaters, gamblers, and syphilitics.

It's the place that proudly displays Barzun's quote, which suggests baseball and America ought to have much more in common than they do.

And, shamefully, it's a place that, after all these years and all he accomplished for the good of the game, still can't find a spot for Marvin Miller.