The recent transit workers’ strike in New York City was a vivid reminder that unions maintain considerable leverage despite their shrinking numbers. Buried beneath the stories about tense negotiations, holiday shopping disruptions and commuters hoofing it over the Brooklyn Bridge was one of labor’s past glories–the creation of Martin Luther King Day. When Transport Workers’ Union president Roger Toussaint demanded recognition of the holiday, he cited the Metropolitan Transit Authority’s failure to honor King’s birthday as evidence of administrators’ lack of respect for the mostly black, Latino and Asian-American members of his union. By doing so, he harked back to the civil rights leader’s working-class activism–and the forgotten labor roots of the MLK holiday.

Given the corporate sponsorship of contemporary King day celebrations, it may come as a surprise that the holiday began as a union demand in contract negotiations. In 1968, just four days after King’s assassination, Representative John Conyers introduced a bill to make the slain leader’s birthday a national holiday. The bill would likely have died in committee, and stayed buried, had it not been for thousands of working-class Americans–most of them black, but also white, Asian and Latino–who risked their jobs over the next fifteen years to demand the right to honor a man they viewed as a working-class hero.

As black union leader William Lucy testified before Congress, King’s prolabor politics gave the holiday a “special significance” for the organized working class. Those politics had emerged from King’s close collaboration in the 1950s and early 1960s with union activists like Bayard Rustin, A. Philip Randolph and Cleveland Robinson, a leader of the New York City-based Distributive Workers of America (DWA). Lucy highlighted that King was shot while supporting a strike in Memphis by members of Lucy’s union, the American Federation of State, County and Municipal Employees (AFSCME).

Initial protests on behalf of a King holiday were small and geographically limited. Managers at a General Motors plant in New York threatened to discipline a small group who refused to work on King’s birthday in 1969, but GM backed down after a larger group walked off their jobs in solidarity a few days later. A few thousand New York City hospital workers went on strike that fall, returning only after managers agreed to higher wages, better benefits and a paid holiday on King’s birthday. Similar contracts were won by 25,000 additional hospital workers and 80,000 dressmakers a few months later.

Unions provided the financial and social capital to extend the movement nationwide. That support was coordinated by DWA leader Robinson, a close friend of the King family. King’s widow, Coretta Scott King, invited Robinson and Conyers to kick off the campaign for a national holiday at a 1969 birthday rally at the new King center in Atlanta. At the rally, Conyers recounted his bill’s defeat in Congress and expressed hope for more support the following year. Robinson called for direct action, declaring, “We don’t want anyone to believe we hope Congress will do this. We’re just sayin’, Us black people in America just ain’t gonna work on that day anymore.”

By 1973, with the King holiday bill still languishing in Congress, working-class blacks were doing just what Robinson recommended. “I have been told by people in plant after plant in Detroit,” Conyers testified in Congress that year, “that on January 15th, if it is not in the bargaining contract, one does not come to work anyway. It is a holiday already.” Robinson’s DWA urged members to observe King’s birthday “regardless of contractual obligations or permissions of employers” and pledged its “full resources” to defend workers from punishment. Union officials demanded a paid holiday in contract negotiations, and individual members were asked to donate a “significant portion” of their holiday pay to the campaign. AFSCME and the United Autoworkers also contributed funds and made the holiday a standard contract demand.

Public employees’ unions were strategically placed to advance the holiday in the 1970s. With growing demand for public health, education and transportation services, state and city workers had gained considerable economic and political clout; their unions helped elect black mayors in Los Angeles, Detroit and Atlanta, and they successfully supported union-friendly officials in New York and other cities. Where officials opposed the holiday, public employees often forced them to acknowledge it. Chicago Mayor Richard Daley ordered city employees to work on King’s birthday in 1971, but public schools closed because of a teachers’ strike that ended with wage and benefits gains–and with a paid holiday on King’s birthday. An Indianapolis union leader boasted that teachers had “negotiated a contract that will allow us to close down schools on Martin Luther King’s birthday.” In 1975 the New Jersey Supreme Court reversed a legislative vote against the holiday on the grounds that it violated union contracts giving state employees the day off.

In 1976 the King center strengthened its alliance with unions by focusing MLK birthday celebrations on the demand for full employment–a centerpiece of the AFL-CIO’s legislative agenda. Thousands of people joined that year’s King day march in Atlanta, with union members as the largest contingent. The event solidified a coalition that helped elect Jimmy Carter President that year. In exchange, President Carter endorsed the national holiday bill and ordered a commemorative stamp to honor King’s fiftieth birthday in 1979.

Carter’s endorsement came as the union movement, which peaked in the mid-1970s, began to lose steam. An urban financial crisis limited mayors’ willingness to negotiate with city workers. In a remarkable attack on the union that helped elect him as Atlanta’s first black mayor, in 1977 Maynard Jackson broke a strike of mostly African-American AFSCME members and replaced them with nonunion workers. Detroit Mayor Coleman Young, himself a former union activist, provoked a strike when he dismissed city workers’ contract demands as “unrealistic” and proposed moving King day to Sunday to relieve the city budget. At the national level, Senator Jesse Helms of North Carolina led a vitriolic attack on the holiday movement and the “epidemic” of “illegal strikes of municipal employees” that seemed to drive it. Helms claimed that another national holiday would be too costly, and inveighed against King as a lawbreaker “subject to influence and manipulation by Communists.”

After a decade of worker organizing for the holiday, it had the legitimacy to survive such attacks. But the campaign took a sharp turn. With union allies weakened, the King center launched an ambitious campaign to generate corporate and popular support for King day. It paid off in 1980, when superstar Stevie Wonder dedicated his hit song “Happy Birthday” to King. In 1982 the King center received large donations from Coca-Cola, the Miller Brewing Company and other megacorporations. The center also gained admission to the Combined Federal Campaign, allowing it to solicit donations from federal employees and members of the military. Coretta Scott King presented Congress with 6 million signatures in favor of a King day bill, the largest petition in favor of an issue in US history. Congress passed the bill, and on November 3, 1983, President Reagan signed it into law.

By the time Martin Luther King Day became a national holiday, few observers remembered its origins in the strike wave of the early 1970s. The corporatizing of King’s image was obvious in the theme of the King center’s 1983 birthday celebration: Free Enterprise: An Agent for Nonviolent Social Change. The AFL-CIO held a dinner to announce its co-sponsorship of a King Labor Institute, but the event was overshadowed by other dinners featuring the likes of Vice President Bush and filmmaker Sir Richard Attenborough. In a particularly ironic twist, the King center secured permission to sell images of King–an outspoken critic of war–on US military bases around the world.

While the edges continue to be smoothed off King’s bracing challenges to racism, war and free-market exploitation, the transit strike recalled the immense symbolic power of Martin Luther King Day, connecting unions to the broader struggle for racial and economic justice. The Metropolitan Transit Authority granted its mostly minority workers the holiday–along with increased wages and pension reimbursements. More than the feel-good celebration of “a dream” that the holiday has become, it was a fitting reminder of a man who believed the struggles for civil rights and for labor rights were intertwined, a man who called the labor movement “the principal force that transformed misery and despair into hope and progress.”