Europeans who settled in the county also used the White River to navigate through the area and trade. Control of the White River lead to military action in the county during the Civil War, including a gunboat battle at Clarendon in 1864. The Flood of 1927 damaged much of the county's settlements along the White, and inundated Clarendon when the levees protecting the city failed on April 20. Conservation efforts by leaders in the county resulted in the creation of federal and state protected areas around the Cache and White rivers, to protect wetlands that could absorb flooding, beginning in 1935. These have been expanded to the current day, as engineers understand more about the positive role of wetlands in floodplain ecology.