Experts say the mass exodus of people from the devastated Gulf Coast region is unprecedented in American history.

Federal officials say up to one million people, mostly from New Orleans, have been displaced in the aftermath of Hurricane Katrina. More than 200,000 victims have taken refuge in nearby Texas, while others are scattered in cities and towns from California to New York City.

War, economic disaster, religious and social persecution and natural catastrophes have forced large populations to relocate many times in American history.

Experts say this time, however, the migration of hundreds of thousands from New Orleans and the U.S. Gulf Coast is completely different - as the newly homeless are coming from one of America's most unique and diverse cities, and it is happening over a much shorter period of time.

Some information for this report provided by AP.