It doesn't matter what Lincoln said, implied, or believed; Genesis is associated with "trailer park racists" and is blamed for slavery and jim crow. Charles Darwin allegedly freed the slaves (right after Voltaire did). The fact that no Black chrstians ever speak up on the creation/evolution issue makes me wonder if maybe they really are left wing intellectuals (who just happen to meet each week at 11am on Sunday mornings) as the Left claims.
Unfortunately for the well-meaning author, the law against returning an escaped slave to his master applied only to Jewish slaves escaping non-Jewish masters outside the Land of Israel.