American Airlines, which can trace its history back to 1926 and Charles Lindbergh, filed for bankruptcy protection through its parent company AMR Corporation it announced today. It's the last of America's major airlines to file.
As with the other airlines that entered bankruptcy in the past few years, the Chapter 11 filing will and AA an opportunity to make their organization more streamlined (i.e. renegotiate labor contracts) and deal with debt issues.
If you're flying AA today there's nothing to worry about as the company will continue to operation normally, which is to say with the typical declining service and flights that take you through O'Hare even if that's nowhere near your destination.