A memorial dedicated to 1,100 Irish immigrants buried in unmarked graves has been officially opened in Colorado. 

Around 500 people gathered in Leadville, Colorado, on Saturday, September 16, to celebrate the completion of the Leadville Irish Miners’ Memorial at Evergreen Cemetery.

Colorado Senator Michael Bennet and Ireland's Ambassador to the US Geraldine Byrne Nason were among those in attendance at Saturday's event, which more than two decades of research and an immense fundraising effort. 

The project was organized by the Irish Network Colorado and pays tribute to "the 1,100 immigrants buried in unmarked graves in the Catholic Pauper section of Evergreen Cemetery, most of whom were Irish."

Miners of Leadville, CO.

Miners of Leadville, CO.

Designed by Irish artist Terry Brennan, the memorial features a spiral walkway leading to glass panels that list the names of miners and their family members who are buried in unmarked graves nearby. The panels surround a bronze sculpture of a miner named Liam, who is kneeling and holding a rock pick tool. 

Approximately 6,000 Irish or Irish American people lived in the bustling mining town of Leadville during the 1880s. According to records, 1,339 migrant workers were buried in unmarked graves in the town, with up to 80% of those estimated to be Irish. Almost half of those buried are children aged 12 or younger, according to the Irish Network Colorado. 

Byrne Nason said many of the Irish buried in unmarked graves in Leadville had fled similar conditions of poverty in Ireland. 

"Ireland had been burdened by centuries of occupation, unrest, exploitation, economic hardship, and most tragically, the Great Famine," Nason said at Saturday's event.

"This devastating period in the mid-1800s, punctuated by crop failures and widespread starvation, either killed or forced millions of vulnerable Irish people to leave the small island that we loved, to seek a new life beyond that homeland.

"This memorial contributes to our shared understanding of what we call the global Irish — the wider story of our diaspora’s journey across the world." 

Irish Network Colorado President Lisa Switzer paid tribute to Dr. James Walsh, a history and political science professor from the University of Colorado who began research for the project more than 20 years ago. 

Walsh said the unmarked graves were "sacred" to the labor community. 

"At Ludlow, the workers were killed by bullets and kerosine, here they died from poverty. To the labor community, this is sacred… the people who died here, they struggled to form unions — this is the breadbasket of the Colorado labor movement right here," Walsh said on Saturday. 

Here is a short documentary from PBS on "The Lost Irish Miners of Leadville":