In the early days of Southern
agriculture,
soil became worn out quickly to the point where it would not support any more
crops. At that point, landowner and
slaves would pack up and move to someplace where the land was still good -- usually
west of the original location. This is one way settlement moved west from the sea
coast in
the South. At this point,
slaves built their own places to live, which very often were the same types of dwelling they'd used in
Africa, clustered together in an
asymmetrical village pattern. The owners didn't care, since it was all
temporary anyway.
However, by the end of the 1700s, the cotton gin had been invented, making large-scale farming with slaves more common; crop rotation was utilised, and people kept farming the same land. Slavery might have gradually disappeared in the South as it already had in the Northern U.S., if not for the cotton gin allowing the high-labor crop of cotton to be processed after picking -- before that the "peculiar institution" had seemed to be on its way out. Now it was economically worthwhile again.
This meant that owners started to care how things were built on their plantations. The "slave quarters" were still poor quality housing; the owners justified this by repeating the common prejudices about how black people were dirty, uncivilized, and would not benefit from improvements. (This seems rather contradictory to the common defense of slavery by saying that it exposed former savages to Christianity and civilization.) But nonetheless, a lot of owners exercised some control over how the living areas of their "property" were arranged.
The owner generally wanted the quarters to be some distance from his own house, but clustered together so that someone (the owner, the overseer, etc.) could keep an eye on the occupants. Many planters dabbled in architecture, which was seen as a "gentlemanly" pursuit; some wanted to apply a bit of the styles of the time to their slaves' houses and others just didn't want a random bunch of shacks completely ruining the look of their own mansion. In any case, rather than the clumped village pattern, planters usually chose to build cabins or barracks on either side of a road, or in neat rows. They were usually downwind from the plantation house, so that any smells (or disease supposedly carried by the wind) would not reach the owning family.
Split-log cabins, perhaps with rocks or mud filling the cracks, were quite common; sometimes other construction such as "rammed earth" or pisé (an African technique) or rough brick were used. For log cabins, the wood pieces were joined together by hand, as nails were quite expensive at the time and would only have been used in the owner's house. The slaves usually did their own construction, and were proud of their skill with the few available materials; it was a way to exercise skills that were not benefiting their owner. (W. E. B. DuBois noted in his 1903 The Souls of Black Folk that many blacks lived in the same type of cabins that they had as slaves.) But since the planter did care about the attitude of the slaves, the construction still had to pass muster. A former Georgia slave recounted the story of a friend on St. Simons Island who tried to build an African hut for himself with wattle and daub walls and a conical thatch roof -- "Massa make him pull it down; he say he ain't want no African hut on he place."
Shutters were all that covered any windows in these cabins, and chimneys were made of sticks and mud, or occasionally brick to reduce fire hazard. Ventilation was obviously pretty bad in these buildings -- terribly hot in the summer but not particularly warm in the winter, and with smoke from any cooking or heating fire going as much into the room as up the chimney. Josiah Henson described it as "The wind whistled and the rain and snow blew in through the cracks, and the damp earth soaked in the moisture till the floor was miry as a pig-sty."
Individual family cabins were usually quite small, ten to twelve feet square or rectangles of similar dimensions housing 8 to 10 people. There might be a loft where some occupants slept, but others would invariably be sleeping on the floor or boards as well on blankets, straw mats, or pallets softened with moss. Francis Henderson said, "My bed and bedstead consisted of a board wide enough to sleep on--one end on a stool, the other placed near the fire. My pillow consisted of my jacket." Two-room cabins would probably house two family groups. Jacob Stroyer noted that "when they did not agree the fires of the two families did not meet on the hearth, but there was a vacancy between them, that was a sign of disagreement."
And yet, "the rules of modesty were held in some degrees by the slaves" (Stroyer) so sometimes scrap wood, quilts, or even old clothes might be used to create some kind of partition, and when barracks-style housing or multi-room shotgun houses were available, the children were separated by gender and slept away from the adults. (Family groups were forced to be quite loose in a situation where spouses or parents and children might be sold away from their former home at any time; some owners purposely tried to break family bonds to decrease conspiracies to escape or revolt, but others encouraged family bonds to keep individuals from wanting to run away.)
The interior might be plastered or whitewashed; there would probably be no decoration, despite the fact that the slaves came from cultures which traditionally had painted, carved, or woven decorations inside their dwellings. A few exceptions might be a horseshoe or other magical object over the door. The hard earth floors might be made with an African method of heating clay over a fire and mixing in cow manure or blood, and then pouring the mixture down to produce a surface said to resemble asphalt.
These small cabins contained most of the cooking; it was rare for there to be a central kitchen where the slaves' food was made, and on the occasions when there was, people still ate in their own cabins. Work such as sewing or carving might be done inside as well. Most gatherings (church services, storytelling, dancing) took place outside the cabins in the "street" they lined up along; it was also not uncommon to have a clearing in nearby woods used for secret meetings at night, with wet quilts hung up around it to muffle sounds. If it was too hot indoors, "they all slept under trees until it grew too cool." (Stroyer)
There was often a double-sized cabin which served as a day care for children whose mothers were working in the fields (as they would be from a few days after giving birth). There was sometimes a "hospital" for sick slaves, but this was no better constructed than the other slave buildings and was just as likely to subject the patient to clouds of insects or other discomforts as their own home was.
Things were somewhat different for house slaves. They were quite likely to be sleeping on the floor in their owner's bedroom or the hallway outside it so as to be available whenever needed. On the other hand, some did have special living quarters in buildings closer to the main house.
In urban settings, the slaves might live at their owner's home or might "live out," renting attics, sheds, or rooms in tenements with money supplied by their owners. Living out was more common for those who were hired out to factories or other work. Their living conditions were probably no better, but the amount of freedom that living out supplied made it highly desirable for slaves (and outlawed in some cities, as well).
If they lived with their owner, their quarters were usually behind the main house, second-floor rooms above kitchens (at the time built separate from the main house to keep the heat down), storage, and even stables. The building was usually brick and better constructed than the slave quarters on a plantation, but having no room to expand within the walled compound caused a lot of crowding in the urban slave quarters. There were usually no windows and only a single door to the outside, so ventilation was pretty much nonexistent. However, many slaves still preferred living in the city just for the increased opportunity for social life in secret gatherings, and decreased supervision -- exactly the things which often bothered their owners.
Sources:
Wright, Gwendolyn. Building The Dream: A Social History of Housing in America. New York, Pantheon Books, 1981.
Stroyer, Jacob. My Life in the South (enlarged edition; Salem, Mass., 1898) http://vi.uh.edu/pages/mintz/14.htm
Drew, Benjamin. A North-Side View of Slavery (Boston, 1856). http://vi.uh.edu/pages/mintz/13.htm
Henson, Josiah. Uncle Tom's Story of His Life": An Autobiography of the Rev. Josiah Henson (London, 1877). http://vi.uh.edu/pages/mintz/12.htm
http://www.uh.edu/collegium/spr00/html/collegium/digging.html
http://cghs.dade.k12.fl.us/slavery/antebellum_slavery/non_plantation_slave_life/housing.htm
http://www.tsha.utexas.edu/handbook/online/articles/view/SS/yps2.html