According to the authors of Louisiana Buildings: 1720-1940, “it was the custom in French Louisiana to have separate housing for the young men of the family as they grew older. Always within the house grounds and sometimes actually connected to the house, a garçonnière was a way of adding living space without the inconvenience or necessity of modifying the original plan.”
This garçonnière at Burnside Plantation, Ascension Parish, Louisiana, was built about 1840. (All photos by Frances Benjamin Johnston via the Carnegie Survey of the South, Library of Congress Prints and Photographs Division; all taken in the 1930s.)
Other often pretty outbuildings in the south included pigeonnieres or dovecotes. “Domestic pigeons had value not only as ornamental birds and a delicacy, but as a source of fertilizer.”
Finally, no pre-twentieth century house could be without one of these little buildings:
Privy, Poplar Forest, Lynchburg, Virginia.