The flood, day by day

The rain starts in the summer of 1926 and doesn't stop. For months the Mississippi basin takes in so much water that its tributaries, from the Missouri to the Ohio, run full. By the spring of 1927, the river is carrying more water than anyone can remember.

The levees are the Delta's great work: miles of earthen walls, built largely by Black laborers, protecting the plantations. Everyone trusts them to hold. In mid-April they begin to give way in several places, and on April 21, at Mounds Landing near Greenville, a huge breach opens. The water races across the lowlands faster than anyone expected.

Within days Greenville is underwater, and the water will stay for months. The flood covers land in seven states, and hundreds of thousands of people lose their homes. The official death toll is under three hundred, but historians believe it was far higher: many Black deaths were never even counted.

Downriver, New Orleans is afraid. To protect the city, on April 29 the authorities dynamite the levee at Caernarvon and deliberately flood St. Bernard and Plaquemines parishes, home mostly to fishermen and trappers. The compensation they were promised came late and fell short.

The water doesn't fully recede until summer. When it does, the Delta is no longer the same. Many who had spent weeks in the refugee camps decide not to go back to the plantations and board the train to Chicago. The 1927 flood is one of the great engines of the Great Migration.