The Civil War occurred during the early stages of the industrial revolution, leading to naval innovations, including the ironclad warship. The Confederacy, recognizing the need to counter the Union's naval superiority, built or converted over 130 vessels, including 26 ironclads. Despite these efforts, Confederate ships were largely unsuccessful against Union ironclads. The Union Navy used timberclads, tinclads, and armored gunboats. Shipyards in Cairo, Illinois, and St. Louis built or modified steamboats.