What is International Workers’ Day?

Mayday, mayday, mayday—we are approaching May Day, and there are still many people out there who don’t know about this international holiday. May Day falls on May 1 and can actually mean different things to different people. For some, May Day is associated with a spring festival where dancing, feasting and wrapping ribbons around a maypole take place. Some may hear the term “mayday” and think of the distress call used by pilots. Still others associate May 1 with Law Day, a time when we reflect on the role of law in our society. 

But globally, May 1 is most widely recognized as International Workers’ Day—a day that honors workers and the labor movements that fought for rights many people benefit from today.

The origins of May Day trace back to labor activism in 1880s Chicago, where workers faced long hours and unsafe conditions. Organizations like the International Working People’s Association and labor leaders such as Albert Parsons, Lucy Parsons and August Spies led the push for an eight-hour workday, culminating in a nationwide strike on May 1, 1886, involving more than 340,000 workers. In Chicago, tensions escalated during strikes at the McCormick Harvesting Machine Company, where police violently confronted workers, leading to multiple deaths and injuries. This unrest culminated in the May 4 Haymarket Square rally—intended as a peaceful protest against police brutality and in support of the eight-hour workday—which turned deadly after violence broke out (APWU, 2025). This incident is referred to as the Haymarket Affair, the Haymarket Massacre, the Haymarket Riot, the Haymarket Square Riot or the Haymarket Incident (Library of Congress, n.d.).

The Haymarket Affair became a defining moment for the global labor movement. In 1889, labor advocates designated May 1 as International Workers’ Day (May Day) to honor those events and to promote solidarity among workers worldwide (APWU, 2025).

While many countries around the world went on to officially establish May 1 as their Labor Day after it was designated by the International Socialist Conference in 1889, the United States took a different path. Globally, May Day became a symbol of workers’ rights and solidarity, but in the United States, its association with socialism and events like the Haymarket Affair made it politically contentious. Instead, following the unrest of the 1894 Pullman Strike, President Grover Cleveland established Labor Day in September as a federal holiday to honor workers without the controversy tied to May Day (The Editors of Encyclopaedia Britannica, n.d.). In the decades that followed, especially during World War II and the Cold War, anti-communist and anti-labor sentiment further distanced the United States from May Day, culminating in President Dwight D. Eisenhower designating May 1 as Law Day in 1958—shifting the focus away from labor movements and toward the rule of law (TeamBonding, n.d.).

Celebrating International Workers’ Day—and reflecting on the struggles that brought it into being—reminds us how far labor movements have come and how much work remains to ensure fairness, dignity and safety for workers everywhere.

Have Students Watch "Why May Day Isn't a National Holiday" (Optional)