The Federal Deposit Insurance Corporation is the U.S. Government agency that insures funds at U.S. banks.FDIC: FAQ

In March 2009, Chairman Sheila Bair indicated that the FDIC could be facing insolvency within the year. In addition, the FDIC has announced new one-time emergency fees for member banks to increase the amount in the fund, while seeking a $100 billion credit line from congress.Bloomberg.com: FDIC's Bair Seeks $100 Billion Credit Line, May Cut Banks Fee (March 6, 2009)

The FDIC was created in the wake of the stock market crash of 1929. In 1933 the corporation was set up to insure depositor's funds in member banks. Banks pay for the fund, which has never received an appropriation from congress in over 75 years. The initial insurance amount was set at $2,500 per depositor. The amount gradually increased with inflation until the most recent change, in 2008, to $250,000 per depositor. 1984 was the first year that the fund paid out more in claims than it took in with premiums from member banks. In 2009 the fund continued to struggle following the closing of 25 banks in 2008.Official Site: About the FDIC