I first read "Out of the Darkness: The Story of Mary Ellen Wilson," which was the "dramatically" told version of this story. More than "historical fiction," I'd refer to it as "creative nonfiction," because the story happened over 137 years ago, and in order to tell the story, someone would have had to be there documenting every person encountered and every word said. I feel that book gave a very accurate description of what happened when this 9-year-old girl was rescued by agents of the American Society for the Prevention of Cruelty to Animals (ASPCA).
This book, however was a natural follow up for me, because after reading Out of the Darkness, I was fascinated, and wanted to read all the newspaper accounts, court transcripts, and other associated documents myself. This all happened three years before Custer's Last Stand at Little Bighorn, just to give you some historical perspective! No cars, electric power, lights, phones. But ASPCA founder Henry Bergh sure knew the media, and he made sure that every newspaper in New York was there to cover this trial.
So my recommendation is: If you enjoy a great story, get Out of the Darkness (also on Kindle). If you want just the facts laid out in a collection of documents, then buy this book. If you're a curious person like myself, then get both!