Answer:
Sharecropping was most common in the South, and especially, in two states: Mississippi, and Tennessee.
In Mississippi, this is due to the large black population. After being freed, many black people still found themselves poor and without a means of subsistance, therefore, they resorted to sharecropping to earn a living.
In Tennessee, both African Americans and White Americans became sharecroppers in large numbers. In that state, poverty was widespread, and poor farmers from both races had little opportunity to own land and make a living by themselves.