Alabama constitution
Article IV: legislative department
Section 95

There can be no law of this state impairing the obligation of contracts by destroying or impairing the remedy for their enforcement; and the legislature shall have no power to revive any right or remedy which may have become barred by lapse of time, or by any statute of this state. After suit has been commenced on any cause of action, the legislature shall have no power to take away such cause of action, or destroy any existing defense to such suit.