Hurricane Katrina has taken its place as the worst natural disaster in American history, an immensity underlined by the unprecedented scope of the recovery plan outlined by President Bush in his speech from New Orleans' Jackson Square on Thursday night. But in many ways, so far little discussed in the national media, it can also be understood as a distinctly Southern disaster, bringing to the fore many of the characteristics that historians say have long defined the Deep South.

Most glaringly, countless articles and photographs have made clear what was always true, if seldom acknowledged: Even as the region has grown in population and economy, it has left hundreds of thousands of people, largely but not exclusively black, behind. Unlike even the rest of the South, vast swaths of the Deep South-including Louisiana, Mississippi, and Alabama, along with parts of Texas, South Carolina, Georgia, and Arkansas-are still mired in the sort of poverty documented over 60 years ago by James Agee and Walker Evans in the Depression-era classic ''Let Us Now Praise Famous Men."

''The Deep South has for a long time been poorer than the rest of the country, and the region has not benefited from growth elsewhere," said historian John Barry, a visiting scholar at Tulane University's Center for Bioenvironmental Research and the author of 1998's ''Rising Tide," a history of the 1927 Mississippi flood. ''In that sense [the aftermath of Katrina] is uniquely Southern."

To be sure, it is easy to read too much into the ''Southernness" of Katrina, and some historians warn that such a focus simply reinforces what they see as the centuries-old effort to use the South as a scapegoat, focusing on its ills while ignoring what are in fact national problems. There are other parts of the country, they note, that are just as poor-according to the 2000 Census, for example, Hartford, Conn., is poorer than New Orleans. But it is in the Deep South, more than perhaps any other region, where poverty, poor health care and education, and a weak social safety net have resulted not just from economic change but a conservative political culture distrustful of government, combined with the residual effects of slavery and Jim Crow.