“One-sixth, and a little more, of the population of the United States are slaves, looked upon as property, as nothing but property. The cash value of these slaves, at a moderate estimate, is $2,000,000,000. This amount of property value has a vast influence on the minds of its owners, very naturally. The same amount of property would have an equal influence upon us if owned in the north. Human nature is the same, people at the south are the same as those at the north, barring the difference in circumstances. Public opinion is founded, to a great extent, on a property basis. What lessons the value of property is opposed, what enhances its value is favored. Public opinion at the south regards slaves as property and insists upon treating them like other property.”

Tales of Mother Goose, 1727, "The Master Cat, or Puss in Boots"

Source: 2000s, A New Birth of Freedom: Abraham Lincoln and the Coming of the Civil War (2000), p. 212

Compromise proposal http://www.civilwarcauses.org/comp.htm#Jefferson%20Davis%20of%20Mississippi (24 December 1860)
1860s

Source: Cannibals All!, or Slaves Without Masters (1857), p. 341

1870s, Third State of the Union Address (1871)

Capitalism: A Treatise on Economics (1996)

As quoted in Autobiography and Personal Reminiscences of Major-General Benj. F. Butler (1892), p. 604

A Human Being Cannot Be Justly Owned (1835)
Context: The slave-holder claims the slave as his Property. The very idea of a slave is, that he belongs to another, that he is bound to live and labor for another, to be another’s instrument, and to make another’s will his habitual law, however adverse to his own. Another owns him, and, of course, has a right to his time and strength, a right to the fruits of his labor, a right to task him without his consent, and to determine the kind and duration of his toil, a right to confine him to any bounds, a right to extort the required work by stripes, a right, in a word, to use him as a tool, without contract, against his will, and in denial of his right to dispose of himself, or to use his power for his own good. “A slave,” says the Louisiana code, “is in the power of the master to whom he belongs. The master may sell him, dispose of his person, his industry, his labor; he can do nothing, possess nothing, nor acquire any thing, but which must belong to his master.” “Slaves shall be deemed, taken, reputed, and adjudged,” say the South-Carolina laws, “to be chattels personal in the hands of their masters, and possessions to all intents and purposes whatsoever.” Such is slavery, a claim to man as property. Now this claim of property in a human being is altogether false, groundless. No such right of man in man can exist. A human being cannot be justly owned. To hold and treat him as property is to inflict a great wrong, to incur the guilt of oppression.

Source: “What’s wrong with Libertarianism”, p. 427