The dream of a waterway across Florida from the Atlantic Ocean to the Gulf of Mexico long has captured the imagination. In 1595 Spanish cartographers depicted one across the peninsula, a mistake assumed correct for nearly 200 years. During the British period in Florida, the royal government conducted a survey to determine if such a route existed, and in 1788 the United States army produced a sketch map of the area, although by that time it was clear no watercourse existed. Later, Thomas Jefferson’s administration exhibited the first high-level American interest in the construction of a waterway—an interest which has continued to the present. Four surveys were completed in the nineteenth century, including one in 1832 while Florida was still...