What surprised me the most, perhaps, while researching my book on Philip Ashton was discovering just how common young captives were aboard pirate ships during the early 1700s. Ashton’s story stands out because of its spectacular details — a young fisherman, captured by one of the worst pirates of the era, escapes and survives as a castaway on an uninhabited Caribbean island. But the more I pursued Ashton’s story, I uncovered the reports of dozens of other young men who were captured by pirate...