MALVERN, Pa. | Young and strapping, the 57 Irish immigrants began grueling work in the summer of 1832 on the Philadelphia and Columbia railroad. Within weeks, all were dead of cholera.
Or were they murdered?
Two skulls unearthed at a probable mass grave near Philadelphia this month showed signs of violence, including a possible bullet hole. Another pair of skulls found earlier at the woodsy site also displayed traumas, seeming to confirm the suspicions of two historians leading the archaeological dig.
“This was much more than a cholera epidemic,” William Watson said.
Mr. Watson, chairman of the history department at nearby Immaculata University, and his twin brother, Frank, have been working for nearly a decade to unravel the 178-year-old mystery.
Anti-Irish sentiment made 19th-century America a hostile place for the workers, who lived amid wilderness in a shanty near the railroad tracks. The land is now preserved open space behind suburban homes in Malvern, about 20 miles west of Philadelphia.