 Samuel Hubbard's Mercantile Exchange Bank eventually became Florida National Bank after Jacksonville's Great Fire of 1901.Millionaire Alfred I. du Pont acquired a major interest in the FNB shortly after moving to Jacksonville in the mid-1920s, but he was unable to gain control until the Great Depression struck in 1929.The FNB stayed solvent throughout the 1930s because du Pont put $15 million of his own money into the institution to cover Bank runs.