Actually most were sharecroppers. And a generation or two later they would flee the south by the millions.
Many were also tenant farmers, renting parcels of land from the owners. But there were many blacks who worked on farms as wage laborers because they (as well as many whites) didn't want to bear the risks of a bad crop. The so-called Black Codes enacted after Reconstruction in the South were in part an attempt by white landowners to limit the free flow of black labor among farms in search of higher wages.
“And a generation or two later they would flee the south by the millions.”
In response both to oppressive Jim Crow laws in the South and the prospects of better pay in the industrializing North.