Rescuers are scouring New Orleans for the last survivors of Hurricane Katrina after what has been called the largest emergency airlift in US history.
Up to 40 aircraft operating around the clock finally cleared thousands from squalid conditions at the Louisiana city's Superdome and convention centre.
Survivors have been telling harrowing tales of violence inside the complex.
President George W Bush has ordered thousands of extra troops to the area, amid criticism of the rescue effort.
The majority of those in most desperate need of relief were impoverished black people who may not have had the means to leave the affected area ahead of Hurricane Katrina.
Civil rights campaigner Jesse Jackson has said racial injustice was to blame for the delayed response to the disaster.
Senior cabinet members, including Secretary of State Condoleezza Rice and Defence Secretary Donald Rumsfeld are due to tour the disaster area, which takes in three states - Louisiana, Mississippi and Alabama.
Ms Rice, the most senior black politician in government, is due to visit the town of Mobile in her home state of Alabama.
The streets of New Orleans were quieter on Sunday after more than 10,000 people were removed from the flood-ravaged city the previous day.
Utilities experts were due to enter the city for the first time to assess the damage caused by Hurricane Katrina and the failure of New Orleans' flood defences.
After spending days without food, water or medicines among rubbish and human waste, survivors appeared stunned as they stumbled towards buses and helicopters.
The exact number of victims is still unknown, but thousands are believed to have died.
The bodies of people who had died while waiting to be rescued could be seen among the survivors just outside the convention centre.
Many survivors said they had witnessed scenes of violence, including rapes and murders at the shelters carried out by criminal gangs.
The BBC's James Coomarasamy in New Orleans says the arrival of thousands of soldiers has finally made a difference by bringing an overdue sense of urgency to the evacuation process.
On Saturday, in a televised address from the White House, Mr Bush acknowledged the response had been insufficient and spoke of an "incalculable" human cost.
More than 10,000 people were rescued from New Orleans
"The magnitude of responding to a crisis over a disaster area that is larger than the size of Great Britain has created tremendous problems that have strained state and local capabilities," he said.
"The result is that many of our citizens simply are not getting the help they need, especially in New Orleans. And that is unacceptable."
The president has signed off a $10.5bn (£5.7bn) emergency spending package approved by Congress.
More than one million people are said to be displaced. Most of them are in Texas, Tennessee, Indiana and Arkansas.
The US has asked the European Union and the Nato alliance to send emergency aid, including blankets, food and water trucks.