Whenever the calendar lands on the fifth month of the year, countries around the world celebrate a holiday called Labor Day or International Workers' Day, lesser-known as May Day -- almost all, except one where the holiday originated: The United States.

Many Americans don't even have the slightest idea what May 1 signifies in their country's history.

Haymarket Riot: The Origin of Labor Day

According to an article, Labor Day is a commemoration of the Haymarket Riot of 1886 in Chicago, where workers organized a massive walkout as part of an effort to fight for an eight-hour workday. A stipulation in which they legally were supposed to have, but was not implemented by their employers who forced them to either work longer or not work at all; better pay and improved working conditions.

The strike took a violent turn when a bomb exploded in the middle of a demonstration and killed at least eight people.

The Haymarket Riot and its aftermath sparked a global outrage among working people and their allies. They started May Day in remembrance to the Haymarket martyrs and their aspirations for the working masses.

Today, over 80 countries across the world celebrate Labor Day or International Workers' Day every May 1, where workers typically get the day off while some organize mass rallies to commemorate the workers' struggle for fair wages and an eight-hour workday.

The Whitewashing of Labor Day

So why is May 1 not a big deal in the United States?

For years, the United States has intentionally whitewashed May Day from its culture and consciousness.

In 1894, after the Pullman Strike in Chicago, President Grover Cleveland declared the first Monday in September a national holiday to celebrate Labor Day. An article says Labor Day was chosen to intentionally co-opt May Day out of fear that commemorating the Haymarket Riot would spark communism and other radical causes.

Other administrations also took action to make sure Americans wouldn't think of May Day. In 1958 President Dwight Eisenhower signed a law making May 1 Loyalty Day, while in the 1980s, President Ronald Reagan declared May 1 as "Law Day."

Finding Haymarket Square where the riot once took place could even be tricky because it no longer exists. Even if protesters plan to wage massive May Day rallies today, they will have a fundamental problem as most Americans have never heard of May Day. Today, most of them go about their day as usual. Sure, some may be encouraged to protest due to their economic woes but never because of some unknown workers and history they never learned about in school.

Although Labor Day is celebrated in the U.S., most people don't think about that aspect of the holiday and use it as an excuse to take a day off and party.

This May 1, while the rest of the world commemorates Labor Day or International Workers' Day, it is worthy of remembering the Haymarket Riot as a piece of U.S. history that gave rise to a global workers' movement.