In Alabama laws are not specifically repealed, but superceded, the most recent law taking precedence. It's usually the last section of an act. For instance, "
And be it further enacted, That all laws or parts of laws, contravening the provisions of this act be, and are hereby repealed." Provisions in other states were likely identical.
In the 1850s Southern legislatures passed a series of laws encouraging free persons of color to seek residence elsewhere or return to slavery.