A Prisoner of Morro; Or, In the Hands of the Enemy is an early adventure novel by Upton Sinclair, written long before his fame as a muckraking author. Set during the Spanish-American War, it follows a daring young American hero who is captured and imprisoned in the grim fortress of Morro Castle in Cuba.
Written for a juvenile dime-novel audience, the story delivers escapes, peril, and heroics against the backdrop of the 1898 conflict that brought the United States onto the world stage. Though slight compared to Sinclair’s later work, it reflects the patriotic adventure fiction popular among young readers of the era. The book offers an entertaining glimpse of how the Spanish-American War was dramatized for the public, and of a famous author’s apprenticeship in popular storytelling.