TUNICA, Miss. (AP) — The bulging Mississippi River rolled into the fertile Mississippi Delta on Tuesday, threatening to swamp antebellum mansions, wash away shotgun shacks, 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, Tenn., just inches short of the record set in 1937. Some low-lying neighborhoods 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 that are 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 $320 million as the serious flooding began, and an official tally won’t 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, federal officials anxiously checked and reinforced the levees, some of which could be put to their sternest test ever.

About 10 miles north of Vicksburg, Miss., contractors lined one side of what is known as a backwater levee with big sheets of plastic to keep 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.

In Vicksburg, at the southern tip of the rich alluvial soil in the central part of the state, the river was projected to peak on Saturday just above the record set during the cataclysmic Great Flood of 1927. The town was the site of a pivotal Civil War battle and is home to thousands of soldier graves.

Wearing rubber boots and watching fish swim up and down his street, William Jefferson stood on a high spot in his neighborhood just outside Vicksburg. He said he had not had a hot meal since water started coming into his house a few days ago. On Tuesday, the house was under at least 3 feet water, as were dozens of other homes in the neighborhood. Nearby, his brother Milton cast a fishing rod.

“At least we can catch something fresh to eat, because we ain’t got no icebox or electricity,” he said with a smile. Then the pair playfully debated whether they would actually eat anything caught in the filthy floodwaters.

“If you eat a fish right now, you won’t live to see the water go down,” William Jefferson said.

Jimmy Mitchell, 46, and his wife and two children have been living in a loaned camper for more than week at a civic arena in Tunica.

“There’s no sewage hookup. You go in a barn to take a shower,” said Mitchell, who is from the small community of Cutoff. “We have no time frame on how long we can stay.”

As Mitchell and friends sat outside chatting in the breeze, children rode bikes nearby.

“Cutoff is a community where everybody lives from paycheck to paycheck. It’s also a community where everybody sticks together,” Mitchell said.

As the water rose, Mississippi Gov. Haley Barbour moved furniture out of his lake house outside Vicksburg on family land that was inundated during the 1927 flood. A week ago, he urged residents to flee low-lying areas, saying that the state wouldn’t assist the evacuations and that people should help one another secure their property and get out.

Widespread flooding was expected along the Yazoo River, a tributary that is backed up because of the bloated Mississippi. Rolling Fork, home of the 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 the nation’s rice, have been swamped over the past few weeks, and the economic impact will be more than $500 million, according to the state’s Farm Bureau.

In Carter, Miss., about 35 miles east of the Mississippi, Scott Haynes, 46, estimated he would spend more than $80,000 on contractors to build levees around his house and grain silos, which hold 200,000 bushels of rice that he can’t get out before the water comes. Heavy equipment has been mowing down his wheat fields to get to the dirt that is being used to build the levees, and he expected nearly all of his farmland to flood.

“That wheat is going to be gone anyway,” he said. “We don’t know if we’re doing the right thing or not, but we can’t not do it.”

Vicksburg National Military Park, where thousands of Civil War soldiers who died in an 1863 battle are buried, was expected to remain dry. The park is the site where Maj. Gen. Ulysses S. Grant’s troops entrapped a Confederate army under Lt. Gen. John Pemberton, forcing its surrender. The victory effectively split the Confederacy in half.

Vicksburg was forecast to see its highest river level ever, slightly above the 56.2-feet mark set in 1927. Farther south in Natchez, forecasters said the 1937 record could be shattered by 4 feet on Saturday.

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 governments $12 million to $13 million in taxes per month, authorities said. That will put some 13,000 employees temporarily out of work

The Mississippi crested in Memphis at nearly 48 feet, just short of its all-time record of 48.7. The figure was preliminary because officials still need to visually inspect the gauge, which was pounded by debris in the river, and the level fluctuates as barges and ships pass by.

Some homes had polluted floodwaters near their first-floor ceilings, while others were completely submerged. Snakes and other creatures slithered in the foul water, and officials warned of bacteria. Nearly 500 people in Memphis were in shelters.

President Barack Obama declared Memphis’ Shelby County and surrounding counties disaster areas, making them eligible for federal aid.

The passing of the crest was of little consolation for many.

“It doesn’t matter. We’ve already lost everything,” said Rocio Rodriguez, 24, who has been at a shelter for 12 days with her husband and two young children since their trailer park flooded.

On the downtown Memphis riverfront, people came out to gawk at the river. High-water marks were visible on concrete posts, indicating that the level was dropping slowly.

“It could have been a lot worse. Levees could have broke,” said Memphis resident Janice Harbin, 32. “I’m very fortunate to stand out here and see it — and not be a victim of the flood.”

Downstream in Louisiana, jail inmates filled sandbags for residents to use to protect their property in St. Martin Parish.

“Everybody is just scared. They don’t know what to do,” said Deputy Sheriff Ginny Higgins, who was overseeing a crew of prisoners.