I'm not much of a Poe enthusiast. I read some of his work in the no doubt extremely simplified "children's illustrated classics" form, but that was a long time ago, and I've never felt any urge to revisit those works. But The Beautiful Cigar Girl is a book about Poe, and one Mary Rogers, a young woman who died in New York in the early 1840s under mysterious circumstances. Her connection to Poe is that he used the circumstances of her apparent murder as the basis for a mystery he wrote a year later, a sequel of sorts to "Murder at the Rue Morgue".
My feeling going into the book was that since Poe's story was going to have the main character solve the murder with his powers of "ratiocination" (deductive reasoning, essentially), and that Poe would actually help the authorities catch the killer with his story. This is not what happens at all.
The book essentially consists of two parallel stories. One is the life and death of Mary Rogers, and the city of New York's subsequent investigation into both. The other is the life of Poe, with the last few chapters devoted to his story, and how he had to hurriedly alter it at the last moment to account for new information. So it's rather a disappointment. There's a lot of pages devoted to recapping the plots of "Murder at the Rue Morgue" and sections of his story about "Marie Roeget", and even more spent on the various wild claims made by the newspapers of the day, and the clashing personalities of the many headstrong editors.
It feels like Stashower didn't have enough new information to justify a book solely on Rogers or Poe, so he put them together. They simply don't overlap much. There are chapters devoted to the investigation into Rogers' death, then chapters about Poe, which mostly consist of him being destitute. He gets work with journals, then feels he's underpaid and gets himself fired. Then he starts drinking, assuming the drinking wasn't the reason he got fired in the first place. The two parts are moderately interesting on their own, but they simply don't entwine in a way that lets the book flow well. Not one of my dad's better suggestions.