Charles Dickens’s A Christmas Carol is so beloved a classic that names like “Scrooge” and “the ghost of Christmas past” have entered our daily lexicon, and we continue to reinterpret the story every few years with everything from cartoon ducks to Muppets.

But Dickens wasn’t the first person to write about holiday-season redemption or ghosts who bring sinners on tours through the past—in fact, those themes were occurring over and over again in the literary journal of mill workers in Lowell, Massachusetts, whom Dickens visited on a tour of America and on whom he heaped praise in his book about his sojourns across the pond.

Did he swipe the mill girls’ stories? Based on new analysis of their collected works, Natalie McKnight and other scholars at Boston University think so.