What was the purpose of the Black Codes? How did President Johnson respond?

Black codes were restrictive laws designed to limit the freedom of African Americans and ensure their availability as a cheap labor force after slavery was abolished during the Civil War. Though the Union victory had given some 4 million enslaved people their freedom, the question of freed blacks’ status in the postwar South was still very much unresolved. Under black codes, many states required Black people to sign yearly labor contracts; if they refused, they risked being arrested, fined and forced into unpaid labor. Outrage over black codes helped undermine support for President Andrew Johnson and the Republican Party.

a.   it resulted in widespread unemployment.

i see, would you mind putting it as one?