Following the War Between the States, the United States Lighthouse Service decided to rebuild the Tybee Island Lighthouse in 1866. Due to increased shipping activity in the South during Reconstruction, the Lighthouse Service reclassified the lighthouse as a First Order light, which needed a tower that was 150 feet above sea level for the nine-foot-tall First Order lens. Since the lower 50 feet of the old 1773 lighthouse remained with its 12-foot-thick walls, 95 feet of new tower were constructed using part of the old tower as its foundation. With the completion of the 145-foot-tall First Order lighthouse in 1867, the Tybee Island Light Station took on a new importance as a major aid to navigation.