Labor Day will draw the final curtain on a historic New York summer in which the Knicks lifted their championship hex, and the World Cup circus came rumbling into town. After months of bonhomie, New Yorkers are afforded one final day of rest before the dreaded return to routine.

Unlike most of the world, which celebrates its workers’ holiday on the first of May, the US takes its repose on the first Monday of September – at the end rather than the beginning of summer. What may first appear to be another case of American exceptionalism, is in fact, rooted in the rich history of Irish labour activism.

As the US rapidly industrialised in the 19th century, the mass influx of immigrants helped shape its growing labour movement. While Germans, Italians and Jews often brought socialist and anarchist ideas, Irish immigrants tended to carry on the traditions of agrarian land activism that had been cultivated under British rule.

The infamous Pennsylvania coal strikes of the 1870s highlighted the strength of this connection, with as many as 20 alleged members of the Molly Maguires – a secret society that had originated in Ireland – later executed for their involvement.

Meanwhile, in the industrial cities Irish immigrants became a cornerstone of America’s working class. Irish workers helped organise unions and led mass walkouts amid the struggle for expanded labour protections.

However, the growth of the American labour movement coincided with the decline of the so-called Gilded Age at the end of the 19th century. The Panic of 1893, an antecedent to the Great Depression, had caused mass unemployment, leading to labour strikes and widespread social unrest.

In New York, Peter J McGuire emerged as a leading figure in the burgeoning labour movement. The son of Irish immigrants, he is credited with organising the first Labor Day parade in New York in 1882. More than 10,000 workers marched in solidarity, demanding expanded workplace protections in a demonstration of union power.

During this period of economic uncertainty the labour movement increasingly shifted towards more racially exclusive membership policies. Unlike many other union leaders, McGuire advocated for “fraternity among the working people regardless of creed, colour, nationality or politics”.

With the holiday approaching its 144th anniversary, American labour is enjoying something of a resurgence

The popularity of Labor Day spread quickly across the country, with US president Grover Cleveland eventually signing the holiday into federal law almost 12 years later. Staunchly anti-labour, he had been instrumental in suppressing strikes. Just days after signing, he deployed federal troops against demonstrators during the Pullman railway strike in Chicago.

While clearly no friend of the unions, Cleveland’s embrace of Labor Day aimed to distance the US from associations with the May Day movement, which was gaining traction among socialists and anarchists across the world.

Nonetheless, soon after Cleveland signed Labor Day into law, a New Jersey paper published an op-ed entitled “Honor to whom honor is due”. It claimed that another Irish labour leader, Matthew Maguire, was in fact the “undisputed author” of the holiday.

The debate centres around the organisation of the parade, with the New Jersey Historical Society claiming that Maguire headed the procession after having gathered many of the estimated 10,000 marchers. Meanwhile, the American Federation of Labor cites a resolution by McGuire from earlier in the year, in which he proposed a street celebration.

Dissenters argue that Maguire’s more radical politics denied him rightful recognition as the father of Labor Day. Having secured the vice-president nomination for the Socialist Labour Party of America, he contested the 1896 election – a move unlikely to endear him to the political establishment.

As the 20th century wore on, McGuire appears to have gained the upper hand in the struggle for posthumous recognition. In 1952 the United Brotherhood of Carpenters and Joiners of America erected a memorial in his honour in New Jersey, which remains the site of an annual Labor Day commemoration. Meanwhile, Maguire’s reputed contributions continue to go largely unnoticed.

Historical debates aside, both men paved the way for future generations of Irish labour activists. Before his involvement in the Easter Rising, James Connolly had emerged as a leading figure in the New York labour movement, establishing the Irish Socialist Federation in 1907. Decades later in 1966, Mike Quill from Kerry etched himself into New York labour history when he led a successful 12-day transit strike, having helped unite black and Irish workers.

With the holiday approaching its 144th anniversary, American labour is enjoying something of a resurgence. Though public support for unions now nears the highs of the 1950s, the US’s comparatively weak labour laws continue to obstruct organising efforts, particularly in the private sector.

Though Labor Day’s provenance remains worth investigating, the two men’s collective legacy outweighs the importance of any lingering historical dispute. All of which is to say: what’s really in a name?