From the gold-mines there, worked by slave labor, came a large share of the riches and luxury of the Roman Empire.
In a word, it was the highest type of the product of slave labor.
slave labor can never be so cheap as what is called free labor.
More than one-half of its territory is wholly unfit for the slave labor; and, therefore, in the nature of things must be free.
The exclusion of slave labor from the mines of California was largely due to the "Columbia-river men."
The chances are that its resources would have been exploited by slave labor.
slave labor and free labor, both combined, are not now able to furnish the quantity needed.
Free labor is far cheaper and more efficient than slave labor.
Another truth demonstrated by political economy is, that free labor is progressive, and slave labor stationary.
The increased value of slave labor, in the culture of cotton and sugar, prevented the realization of this expectation.