William H. Seward: Human

On the Irrepressible Conflict (1858)
Context: As a general truth, communities prosper and flourish, or droop and decline, in just the degree that they practise or neglect to practise the primary duties of justice and humanity. The free-labor system conforms to the divine law of equality, which is written in the hearts and consciences of man, and therefore is always and everywhere beneficent.
The slave system is one of constant danger, distrust, suspicion, and watchfulness. It debases those whose toil alone can produce wealth and resources for defence, to the lowest degree of which human nature is capable, to guard against mutiny and insurrection, and thus wastes energies which otherwise might be employed in national development and aggrandizement. The free-labor system educates all alike, and by opening all the fields of industrial employment and all the departments of authority, to the unchecked and equal rivalry of all classes of men, at once secures universal contentment, and brings into the highest possible activity all the physical, moral, and social energies of the whole state.