Carysfort Reef Light stands east of Key Largo on one of the most hazardous stretches of the Florida Reef, where shipwrecks were especially frequent long before the tower was built. Congress first tried to mark the site with lightships beginning in the 1820s, but service there was isolated and dangerous; during the Second Seminole War, keeper John Whalton was killed while ashore on Key Largo. Construction of the permanent iron-pile lighthouse began in 1848, and Lieutenant George Meade completed it in 1852. The light remained in service until 2015, becoming the oldest functioning lighthouse of its type in the United States before its decommissioning.