Plantation complexes in the Southern United States refers to the built environment (or complex) that was common on agricultural plantations in the American South from the 17th into the 20th century. The complex included everything from the main residence down to the pens for . A plantation originally denoted a settlement in which settlers were "planted" to establish a colonial base. Southern plantations were generally self-sufficient settlements that relied on the forced labor of slaves, similar to the way that a medieval manorial estate relied upon the forced labor of serfs.
Today, as was also true in the past, there is a wide range of opinion as to what differentiated a plantation from a farm. Typically, the focus of a farm was subsistence agriculture. In contrast, the primary focus of a plantation was the production of cash crops, with enough staple food crops produced to feed the population of the estate and the livestock. A common definition of what constituted a plantation is that it typically had 500 to 1,000 acres (2.0 to 4.0 km2) or more of land and produced one or two cash crops for sale. Other scholars have attempted to define it by the number of slaves that were owned.
The vast majority of plantations did not have grand mansions centered on a huge acreage. These large estates did exist, but represented only a small percentage of the plantations that once existed in the South. Although many southern farmers did own slaves prior to emancipation, few owned more than five. These farmers tended to work the fields alongside their slaves. Of the estimated 46,200 plantations known to exist in 1860, 20,700 had 20 to 30 slaves and only 2,300 had a workforce of a hundred or more, with the rest somewhere in between.
Many plantations operated by absentee-landowners never had a main house on site. Just as vital and arguably more important to the complex were the many structures built for the processing and storage of crops, food preparation and storage, sheltering equipment and animals, and various other domestic and agricultural purposes. The value of the plantation came from its land and the enslaved people (later sharecroppers or tenants) who toiled on it to produce crops for a profit. These same people produced the built environment, from the main house for the plantation owner, the slave cabins, barns, and other structures of the complex.