• The commerce of a free people is many times more valuable than that of slaves. Freemen produce and consume vastly more than slaves. They have therefore more to buy and more to sell. Hence the free states have a direct pecuniary interest in the civil freedom of all the other states. Commerce between free and slave states is not reciprocal or equal.

    Lysander Spooner (1845). “The Unconstitutionality of Slavery”, p.130