By Freya McClements
US researchers have now uncovered the precise location of the grave
In 1832, 57 emigrants from Donegal, Derry and the surrounding counties set sail for a new life in America.
They found work on the railroads, but within weeks they were all dead, struck down by cholera - or possibly even murdered by locals who believed the immigrants had brought the disease with them.
The men were buried where they had died, in a mass unmarked grave along 'Duffy's Cut', the section of the Philadelphia and Columbia railroad they helped to build.
For the last five years, Dr Frank Watson, his brother William, and a team from Immaculata University in Pennsylvania have been searching for the men's remains - and on Friday, they made the breakthrough they were waiting for.
"We discovered the first two skulls," said Dr Watson.
"I myself was able to pull out of the first grave the skull of a man who we believe was called John Ruddy, an 18-year-old who came over as a labourer from Donegal to work on the railroad.
The story of Duffy's Cut
June 1832: Irish immigrants arrive in the US
August 1832: 57 men die along the railroad and are buried in an unmarked mass grave
2002: Researchers at Immaculata University begin searching for the men's bodies
2009: Bones discovered at the Duffy's Cut site
"We also found the skull of an adult man and some leg and toe bones, and a good bit of one of their skeletons."
For Dr Watson and the rest of his team, it was an emotional moment.
"It was almost like a dream.
"There was excitement mixed with sadness that these poor men ended up in such an ignominious site, dumped alongside a hillside at Duffy's Cut.
"But it was also joyous, because we'll now be able to commemorate these men and remember them.
"What we would hope to do is to return some of the bones of these Irishmen back to their native land," said Dr Watson.
Brian Hegarty's great-great-uncle Bernard left Derry in 1832 to work on the railroad.
They may never know for certain, but the Hegarty family believes he may have been one of the men who died at Duffy's Cut.
Two skulls as well as leg, toe and other bones have been found at the site
"Our family got a letter from him just after he arrived in America to say that he'd found work on the railroad, and that was it.
"They never ever heard from him again.
"Whether he did die there or not, it's a fantastic breakthrough, absolutely remarkable.
"With the advances in DNA testing they might be able to identify them and to even trace relatives, and we might find that there are still relatives alive here in Ireland.
"It would be incredible if some of the bodies could now be brought home and reinterred on consecrated ground," said Mr Hegarty.