The "merchandise" cost little in the country of production, and the returns were considerable.
But, necessary as was the foundation of the colonies beyond the sea from all points of view, it could not justify those markets for human flesh.

Generous voices soon made themselves heard, which protested against the trade in blacks, and demanded from the European governments a decree of abolition in the name of the principles of humanity.
In 1751, the Quakers put themselves at the head of the abolition movement, even in the heart of that North America where, a hundred years later, the War of Secession was to burst forth, to which this question of slavery was not a foreign one.

Different States in the North--Virginia, Connecticut, Massachusetts, Pennsylvania--decreed the abolition of the slave trade, and freed the slaves brought to their territories at great expense.
But the campaign commenced by the Quakers did not limit itself to the northern provinces of the New World.

Slaveholders were warmly attacked beyond the Atlantic.

France and England, more particularly, recruited partisans for this just cause.