According to the Flag Institute, a leading research centre that manages the United Kingdom Flag Registry, it is a "relatively recent idea" that the flag is only a jack when flown from a warship.
The race resumed with three laps to go, and the final accident occurred with Regan Smith leading as he headed out of the final turn to the checkered flag.
The Confederate flag has also become an issue in the Republican campaign, but both leading contenders, George W Bush and John McCain, have said it is up to South Carolina residents to decide whether the flag should fly.