More than a quarter century of “labor peace” in Major League Baseball died on Dec. 2, when owners locked the players out after the sport’s collective bargaining agreement expired without the league and the Major League Baseball Players Association reaching a new deal.

While the imposition of a lockout was jarring after this long period of harmony, it was simply the latest chapter in a battle that dates back to the 1870s — one that included a whopping eight work stoppages between 1972 and 1995.

In many ways, the twists and turns of baseball’s labor battle over salaries, pensions and more have reflected the ebbs and flows of labor power in the United States.

In 1879, National League team owners established the then-secret “reserve clause” as part of players’ contracts. Teams could reserve five players on their rosters to prevent other teams from poaching them. Owners claimed they could exercise their option to renew these players in perpetuity. By the 1890s, they inserted this reserve clause in every player contract.

Players balked over this absolute control — just as workers in other industries were battling corporate control as part of the nascent and growing union movement. Players were well aware of the changes in labor in the United States, in part because professional baseball was not a full-time career: players held regular jobs in the offseason.

In 1890, John Montgomery Ward sued the New York Mets. The New York Supreme Court decided in Ward's favor, ruling that his 1889 contract was “harsh and inequitable.” Ward had played the 1890 season in the upstart Players League, but the player-led league folded after one season and the Ward decision faded into obscurity.

Instead, MLB won five cases over the next 60 years — Chase v. White Sox (1914), Federal Baseball v. National League (1922), Gardella v. Chandler (1949), Toolson v. New York Yankees (1953) and Flood v. Kuhn (1972) — strengthening the grip of the reserve clause. These victories reflected how the Sherman Antitrust Act (1890) became a tool for corporations to bust unions, despite Congress intending for it to enable breaking up business monopolies.

In Chase v. White Sox, the New York Supreme Court decided baseball did not constitute interstate commerce under the Sherman Act and thus the sport was exempt from any antitrust litigation. The U.S. Supreme Court concurred in Federal Baseball, which became the basis for MLB’s future victories and the league’s exemption from antitrust laws.

Several times during this period, MLB players attempted to organize collectively to bolster their leverage in fighting owners’ monopoly power. But the Brotherhood of Professional Base Ball Players, the Players’ Protective Association, the Fraternity of Professional Baseball Players of America and the American Baseball Guild all failed to take hold. One MLB Commissioner, A.B. “Happy” Chandler, actively worked to forestall union activity by hiring antilabor spies to prevent a strike in 1946.

But in 1965, players formed the MLBPA and the next year, they made a crucial hire for the MLBPA’s first executive director: Marvin Miller, who had made his career working for the United Steelworkers union. Miller made the players association a powerhouse, changing the culture of the sport by valuing players’ work and their rights as employees.

Within two years, Miller successfully negotiated the first collective bargaining agreement between the MLBPA and team owners, covering the 1968 and 1969 seasons. Most importantly, the agreement included an arbitration procedure for grievances and raised minimum player salaries.

In 1970, the union reached a new two-year agreement with the owners. That same year, Miller supported Curt Flood of the St. Louis Cardinals, who sued to challenge yet again the legality of the reserve clause. Flood wanted the right to consider offers from all teams as a free agent, but he understood owners might blackball him and was hoping to blaze a path for the players coming after him.

Flood lost, but the outcome made clear that only union activity could break the grip of the reserve clause. While no active players testified on Flood’s behalf, on March 31, 1972, as the Supreme Court considered Flood’s case, the MLBPA voted to strike for the first time because owners would not agree to raise pension benefits in the next collective bargaining agreement.

The move proved successful when, after 13 days of missed games, the owners agreed to increase pensions and allow salary arbitration for players who had completed two seasons.

In 1973, owners locked out players during spring training over issues with salary arbitration, showing that they would not concede their control without a fight.

Two years later, however, the salary arbitration for two players, Andy Messersmith and Dave McNally, finally broke the chokehold of the reserve clause. On Dec. 23, 1975, Arbitrator Peter Seitz interpreted the players’ contracts as one-year agreements, destroying the 96-year practice of clubs renewing contracts in perpetuity.

The ruling sent shock waves through the sport. When the existing labor agreement ended in early 1976, players who had not signed contracts for the 1976 season — around 350 — became free agents. The owners locked out the players during spring training, but the parties reached a compromise: Players would gain free agency only after six years of service.

This detente was just temporary, however. In 1980, 1981 and 1985, players struck to fight off owners’ campaign to end free agency in its infancy and roll back salary arbitration. Most notably, the 1981 strike over owners’ desire for a compensation scheme for losing free agents cost the sport 713 games and postponed the All-Star Game.

And even that work stoppage paled in comparison with the most bruising battle in the 20-year labor war: the player strike that began in August 1994. For the eighth time in 20 years, the sport came to halt, and this time it led to the cancellation of the World Series. Owners claimed free agent salaries were out of control and demanded a salary cap. The players wouldn’t budge, and when the conflict remained unresolved by the beginning of spring training in 1995, the owners recruited replacement players — scabs — to gain leverage. Finally, an injunction by U.S. District Judge Sonia Sotomayor, a future Supreme Court justice, ended the conflict, leading to a compromise agreement that ended two decades of labor wars.

For 26 years, both sides, scarred by the damage done by losing the 1994 World Series — and bolstered by skyrocketing revenue — have completed collective bargaining agreement negotiations without a work stoppage.

This fractious relationship between players and management has reflected the larger state of worker-management relations in the United States. For example, players witnessed strikes by 3 million workers in the United States in 1970. Politics were similarly influential. These players had lived through the civil rights movement and the Vietnam War. Curt Flood had participated in NAACP events with Jackie Robinson. Roguish characters like Jim Bouton were outspoken in the 1960s and 1970s whether baseball liked it or not.

Similarly, the sport’s labor peace followed a decline of union popularity and power in America as a result of the twin blows of deindustrialization and President Reagan crushing the Professional Air Traffic Controllers Organization (PATCO) strike in 1981. As late as 1983, 1 in 5 American workers still remained union members. But over the past four decades, that number has dropped by half, per the Bureau of Labor Statistics, reducing workers’ rights alongside dwindling membership. The other major U.S. sports all experienced work stoppages during this period, but generally, players came out the losers from these conflicts.

In 2021, labor is experiencing a resurgence, including strikes at John Deere, Frito Lay, Kellogg and Columbia University; a narrowly avoided strike threat by the International Alliance of Theatrical and Stage Workers (IATSE); and unionizing campaigns by workers at Amazon and Starbucks, as well among health-care workers. (Amazon founder Jeff Bezos owns The Washington Post.)

Sports labor battles occur in the broader culture around work, fair pay, retirement and strikes. The dramatic workplace changes wrought by the coronavirus have affected professional sports, from the highest level to the minor leagues — the latter including players who are also gig workers when they aren’t in uniform. Similarly, the role of data and technology has enhanced the leverage of management in many industries, including sports. Furthermore, athlete activism regarding working conditions is also experiencing a resurgence thanks to the stands taken by those such as Naomi Osaka and Simone Biles.

While there isn’t necessarily a direct tie between resurgent labor activism in 2021 and the unique disagreements that produced an impasse between baseball players and owners, at its core the division between the two sides reflects the current gulf between businesses and employees, one which we see reverberating throughout American workplaces.