In Louisiana, hundreds were rescued from rising waters, and the rescues are continuing into the weekend. In New Orleans, the levee system held up and the town was spared any major damage.
In Mississippi, emergency crews are keeping a close eye on the dam on Lake Tangipahoa, damaged by the tropical depression. Crews are working on a controlled release to ease the pressure. The dam could release a 17-foot flood crest downstream in Louisiana if it were to give way.
In Louisiana alone, the storm cut power to 901,000 homes and businesses, or about 47 percent of the state, but that was down to 617,000.
More than 15,000 utility workers began restoring power to customers in Louisiana and Mississippi, but officials said it would be a couple of days before power was fully restored.
Newly nominated Republican presidential candidate Mitt Romney visited flood-ravaged communities, and President Barack Obama said he would arrive Monday, appearances this part of the country is all too familiar with after Katrina and the Gulf oil spill.
Isaac dumped as much as 16 inches of rain in some areas, and about 500 people had to be rescued by boat or high-water vehicles. According to the National Weather Service, the storm will continue to pack rain and bring the threat of flash flooding as it heads across Arkansas into Missouri and then up the Ohio River valley over the weekend.
At least five deaths were reported in Louisiana and Mississippi.
The latest two victims, a man and a woman, were discovered late Thursday in a home in the hard-hit town of Braithwaite, south of New Orleans. Authorities said deputies went to search for the couple after someone reported they had apparently not escaped the flooding. Their names were not immediately released.
ABC News and The Associated Press contributed to this report.