The bulging Mississippi River has rolled into the fertile Mississippi Delta, threatening to wash away homes and destroy fields of cotton, rice and corn in a flood of historic proportions.
The river took aim at one of the most poverty-stricken parts of the country after cresting before daybreak at Memphis, Tennessee, just inches short of the record set in 1937. Some low-lying neighbourhoods were inundated, but the city's high levees protected much of the rest of Memphis.
Over the past week or so in the Delta, floodwaters along the rain-swollen river and its backed-up tributaries have already washed away crops, forced many people to flee to higher ground and closed some of the dockside casinos vital to the state's economy.
But the worst is yet to come, with the crest expected to roll through the Delta over the next few days. The damage in Memphis was estimated at more than £196 million as the serious flooding began, and an official tally will not be available until the waters recede.
To the south, there were no early figures on the devastation, but with hundreds of homes already damaged, "we're going to have a lot more when the water gets to where it's never been before", said Greg Flynn, a spokesman for the Mississippi emergency management agency.
Across the region, government officials anxiously checked and reinforced the levees, some of which could be put to their sternest test ever.
Just north of Vicksburg, Mississippi, contractors lined one side of what is known as a backwater levee with large sheets of plastic to prevent it from eroding if floodwaters flow over it as feared - something that has never happened to the levee since it was built in the 1970s.
Widespread flooding was expected along the Yazoo River, a tributary that is backed up because of the bloated Mississippi. Rolling Fork, home of the legendary bluesman Muddy Waters, was also in danger of getting inundated.
Farmers built homemade levees to protect their corn, cotton, wheat and soybean crops, but many believed the crops would be lost entirely. More than 1,500 square miles of farmland in Arkansas, which produces about half of America's rice, have been swamped over the past few weeks, and the economic impact will be more than £307 million, according to the state's Farm Bureau.
The state's key gambling industry took a hit. All 19 casinos along the river will be shut down by the end of the week, costing authorities £7.4 to £8 million in taxes a month, authorities said. That will put some 13,000 employees temporarily out of work.