Eugene V. Debs, union leader and five-time Socialist Party presidential candidate, understood the importance of Labor Day better than anyone else. But have you ever wondered why we celebrate Labor Day on September 7 every year? Why not May 1, the day of international solidarity with all workers? Or April 12, the birthday of Robert Burns, a popular Scottish poet who championed working-class people in his poems?

The history of this holiday reveals that it was intended to honor and celebrate the birth of unions, which were a radical idea at the time. In June 1869, after two years of planning by an alliance of trade union leaders called the Central Labor Union, social reformers and self-proclaimed socialists held what they dubbed as “the first labor festival in U.S. history” in New York City. It was a massive outdoor meeting that included an eight-hour work day march and culminated with a giant banquet for 10,000 people.

The organizers hoped to demonstrate the power of unions by rallying large crowds on this special occasion. Labor Day commemorates the importance of labor unions as well as workers’ achievements and the power they possess. It’s important to note that, at the time, only 6 percent of American workers were unionized and working conditions were terrible in most jobs. In 1870, the Cincinnati Daily Gazette described a first-hand account by immigrant German workers of “groping around for an existence” on $4 per week. The wives and children of these workers were often forced to sell flowers, candy or fruit on the streets to earn money for their families. Occasionally, when they were allowed to work, these women earned as little as $0.25 a week in factories. But some people believe that American Labor Day had its roots in ancient pagan celebrations marking the beginning of the harvest season.