Black Code

noun U.S. History. (in the ex-Confederate states)
  1. any code of law that defined and especially limited the rights of former slaves after the Civil War.
Compare Jim Crow law.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Word Origin and History for black code
n.

local or state legal restrictions on black persons, free or slave; attested by 1840, American English, though the thing itself is much older.

Online Etymology Dictionary, © 2010 Douglas Harper