4) It provides insurance against any banks that fail.
The Federal Deposit Insurance Corporation was created in the early 1930s when almost a third of American banks had collapsed and failed, and consequently, American consumers had lost trust in the banking system. As a response to this, Roosevelt's administration created the 1933 Banking Act, which formed the FDIC, with the purpose to provide stability to the U.S.'s economy.
The corporation, still in force nowadays, provides deposit insurance to depositors in U.S. commercial banks and savings institutions in case that a bank fails, and regulates some banking practices as well.