After slavery was abolished, many black families labored as sharecroppers or tenant farmers. They gained some independence, no longer working in gangs of laborers, but were often at a disadvantage in negotiations with white planters, as they were generally illiterate. Planters advanced them supplies and seed at the beginning of the season, allowed them to buy other goods on credit, and settled with them at the end of harvest for a major portion of the crop. Historian Nicholas Lemann writes "segregation strengthened the grip of the sharecropper system by ensuring that most blacks would have no arena of opportunity in life except for the cotton fields" (p. 6).