The roots of the iconic palmetto tree (Sabal palmetto) go deep in the history of Charleston. The indigenous trees were used to construct Fort Moultrie. During the American Revolution, the defense of the fort was successful largely due to the absorption of British cannonballs by the palmetto walls. This inspired its addition to the South Carolina state flag in 1861 and its designation as the official state tree in 1939. Today, the palmetto tree has grown into a symbol of South Carolina heritage.