1520s, "act of abolishing; state of being abolished," from French abolition or directly from Latin abolitionem (nominative abolitio) "an abolition, an annulling," noun of action from past-participle stem of abolere "destroy" (see abolish). Related: Abolitionary ("destructive"); abolitional ("pertaining to abolition").
Specific application to "opposition to the trans-Atlantic African slave trade" as a political question is first attested 1788. By 1823 abolition was being used in regard to proposals or arguments to end American slavery itself, and after 1832 this was the usual sense of the word until the effort was accomplished by the 13th Amendment (1865). The alternative noun abolishment (1540s) seems not to have acquired a special use in reference to slavery issues.