During the 19th century, because this entire area consists of fertile floodplains and a climate of long, hot summers, and adequate rainfall, the Covington area and the rest of West Tennessee were developed for cotton plantations. This became the primary commodity crop across the South in the 19th century, generating great wealth for many large planters. African-American slaves were brought to Western Tennessee by planters relocating here, or forced here by sale in the domestic slave trade. West Tennessee was the center of large-scale slavery in Tennessee, and Memphis had a major slave market. Planters and farmers in Middle Tennessee also held slaves, although in fewer number. Farmers in the eastern part of the state mostly developed small subsistence farms and held few slaves.