The desire for freedom was in the mind of nearly every enslaved negro. Liberty was the subject of the dreams and visions of slave preachers and sibyls; it was the object of their prayers. The plaintive songs of the enslaved race were full of the thought of freedom. It has been well said that "one of the finest touches in _Uncle Tom's Cabin_ is the joyful expression of Uncle Tom when told by his good and indulgent master that he should be set free and sent back to his old home in Kentucky. In attributing the common desire of humanity to the negro the author was as true as she was effective."[47] To slaves living in the vicinity, Mexico and Florida early afforded a welcome refuge. Forests, islands and swamps within the Southern states were favorite places of resort for runaways. The Great Dismal Swamp became the abode of a large colony of these refugees, whose lives were spent in its dark recesses, and whose families were reared and buried there. Even in this retreat, however, the negroes were not beyond molestation, for they were systematically hunted by men with dogs and guns.[48] Scraps of information about Canada and the Northern states were gleaned and treasured by minds recognizing their own degradation, but scarcely knowing how to take the first step towards the betterment of their condition. [47] Rhodes, _History of the United States_, Vol. I, p. 377. [48] F. L. Olmsted, _Journey in the Back Country_, p. 155; Rev. W. M. Mitchell, _The Underground Railroad_, pp. 72, 73; M. G. McDougall, _Fugitive Slaves_, p. 57. There can be no doubt that the form in which slavery existed in the South during the opening decade of the present century was comparatively mild; but it is quite clear that it soon exchanged this character for one from which the amenities of the patriarchal type had practically disappeared. With the rapid expansion of the industries peculiar to the South after the opening up of the Louisiana purchase, the invention of the cotton gin, and the removal of the Indians from the Gulf states, came the era of the slave's dismay. The auction block and the brutal overseer became his dread while awake, his nightmare when asleep. That his fears were not ill founded is proved by the activity of the slave-marts of Baltimore, Richmond, New Orleans and Washington from the time of the migrations to the Mississippi territory until the War. Alabama is said to have bought millions of dollars worth of slaves from the border states up to 1849. Dew estimated that six thousand slaves were carried from Virginia, though not all of these were sold to other states.[49] [49] Edward Ingle, _Southern Side-Lights_, p. 293.