Ireland may not be one of the most massive countries, but it sure does have a ton of personality.

Its folklore is widely known, and the Irish accent is a highly imitated one. It is a European region that has gone through generations of cultural unrest involving oppression, civil wars, and famine. However, that has not impacted this country’s residents’ cheerful disposition, as they have a reputation for being some of the most friendly people you will ever meet.

Though Irish culture is full of unique sayings such as may the road rise to meet you, the most famous one associated with these affable people is one that stems from outside of Ireland’s borders. 

It does not matter where you live. If you have a TV and have watched North American or British entertainment, you have likely heard the saying – the luck of the Irish. Alternatively, it may have reached your ears when you have found yourself inside a casino with an Irishman eager to play slots. Below, we go through the most likely origins of this renowned expression.

The California Gold Rush Theory

The California Gold Rush was a search for precious metals that began in 1848 and ended seven years later. It got spurred on by the gold discovery at Sutter's Mill in Coloma by James W. Marshall. That occurrence immediately caused people to rush (pun intended) to this US state in search of riches. Such an instant influx of gold and people re-energized the US economy, allowing California’s population to jump. 

According to some estimates, during this period, hundreds of thousands of Irish people left their homeland for a better life in America, as this was around the same time as Ireland’s great potato famine. Many of these Irish came to California and compromised 13% of San Francisco's population and more than 21% of its labor force in 1870. Edward T. O’Donnell, a History Professor from Holy Cross College, claims that the origin of the term – luck of the Irish, stems from the fact that many successful gold rush miners were either Irish or of Irish-American birth. That caused the locals to believe that their luck may somehow tie into their lineage.  O’Donnell thinks the term itself originally carried derision toward Irish miners. It was in no way meant as flattery.

The Bad Luck Theory

There is no doubt that Edward T. O’Donnell’s theory holds the most water. Nevertheless, others think that this expression refers to the Irish's lack of luck in the 19th-century. Many Irish felt that their presence in the US was undesirable. They got cast out by locals, finding themselves scraping for employment, which led them to alcoholism. Others fell ill. Those back home lost loved ones due to the widespread famine and barely made ends meet. This tragic story of the Irish settlers in the US got used as the basis for a phrase that meant having poor luck. At first, it was exclusive to the US, but now it has attained a global scope.