Thousands of National Guard troops have been fanning out across Florida to help assess the damage in one of the states battered by Hurricane Dennis.
The clean-up operation is already under way
Downgraded to a tropical depression, experts say Dennis is now moving northwards and may still be dangerous.
Florida, Mississippi and Alabama have been declared disaster zones, allowing them to receive emergency federal aid.
At least four people were reported to have died in the US. At least 27 had already been killed in Cuba and Haiti.
Some 1.4 million people were evacuated ahead of its arrival in the US.
Dennis roared through north-west Florida and the Alabama coastline, knocking out power lines but causing less damage than first feared.
Roofs went flying and trees fell as the winds hit, but the devastation of last year's Hurricane Ivan was not repeated.
Experts said that although winds had reached the same speeds it caused less damage because it was more compact and faster moving.
The hurricane has now been downgraded to a tropical storm
The storm cut power to half a million homes and businesses, with some told it could be three weeks before supply is restored.
Crews working for US oil and gas producers have returned to the Gulf of Mexico to begin work on platforms paralysed by the storms.
Forecasters warn the mass of tropical storms could bring strong winds, heavy rains and possibly tornadoes.
Dennis is expected to travel north from Mississippi through Tennessee, Illinois, Kentucky and Indiana.
The US National Hurricane Centre said flood and flash warnings were in effect for sections of Alabama, Arkansas, Georgia, Mississippi, South Carolina and Tennessee.
Florida Governor Jeb Bush warned that many of those forced to live in temporary homes since Ivan hit might again be the worst affected.
"A lot of people are going to hurt, particularly the hundreds of thousands who live in trailers," he said.
But the predominant message was one of relief that the storm had not caused the same scale of devastation as Hurricane Ivan 10 months earlier.
'Dodged the bullet'
It made landfall on Sunday with a storm surge of up to 4.6m (15ft) near Pensacola Beach, Florida.
"We dodged the bullet on the most part although our beach has suffered badly again," said Sara Comander, a spokeswoman for Walton County, east of Pensacola, speaking to AP news agency.
One man was electrocuted in Fort Lauderdale, Florida, after stepping on a cable brought down by the winds, AP news agency reported.
Sixteen people, including an 18-day-old baby, are known to have died when the hurricane hit the southern coast of Cuba on Friday.
More than 500,000 Cubans were moved from the path of the hurricane, which damaged buildings and knocked out power.
On Thursday, the hurricane thrashed the Dominican Republic and southern Haiti, where at least 11 people died when rivers burst their banks, flooding homes, and roofs were torn off buildings.
Dennis was the Atlantic's first hurricane this year and is the strongest to form in the Atlantic this early in the season since records began in 1851, the US National Hurricane Center (NHC) in Miami said.