Ceremonies on Friday marked the ninth anniversary of Hurricane Katrina.
In New Orleans, Mayor Mitch Landrieu and Julian Castro, the secretary of the U.S. Department of Housing and Urban Development, attended a morning wreath-laying ceremony at the Katrina Memorial on Canal Street near City Park Avenue, where scores of unidentified Katrina victims are entombed.
"The most incredible thing that the people of New Orleans have done is said I'm not quitting, and I'm staying, and I think it's manifest in the buildings that are going up and the schools that are rebuilt, but really it's the spirit of the people," Landrieu said.
"It has been amazing to see the progress that has been made over the last nine years because of the efforts of the leadership here as well as the citizenry of New Orleans," Castro said.
Many of the more than 1,800 who died were in the New Orleans area, where levee failures contributed to catastrophic flooding.
The storm did billions of dollars' worth of damage in Louisiana and in Mississippi, where coastal homes were wiped out.
Memorials in Mississippi included a series of events at the Ground Zero Museum in Waveland.
(The Associated Press contributed to this report.)