St. Marks Light stands on Apalachee Bay at the mouth of the St. Marks River in Florida as the state’s second-oldest light station. Authorized in 1828 to guide shallow, difficult coastal traffic serving the plantation economy, it was first successfully completed and lit in 1831. The station endured repeated threats, including fears during the Second Seminole War, shoreline erosion that forced relocation inland in 1842, severe hurricanes, and Civil War damage after Confederate forces disabled the light in 1865. Rebuilt and later automated, it eventually passed to the U.S. Fish and Wildlife Service, was deactivated in 2016, and now shines seasonally after restoration.