The slave population of the United States increased from 698,000 to 3,954,000 between 1790 and 1860, and 75 percent of these enslaved people worked as agricultural laborers growing cotton, sugar, rice, tobacco, and hemp. The majority of these, moreover, worked in cotton. About 15 percent of southern slaves were classified as domestic servants, and approximately ten percent worked in commerce, trades, and industry--principally in towns and cities. This map shows the heavy concentration of slaves in plantation districts, in which the majority of the enslaved lived on plantations of between 20 to 150 slaves. This so-called "black belt" (so named because of the rich, dark soil and the domination of enslaved blacks in the population) swept across the southern states from Virginia to Texas. In some of these areas, enslaved blacks outnumbered whites 13 to 1. Students and teachers may want to use this map in conjunction with the other maps and "in-depth" historical essays available on the site. As you look at the map, think about these Points to Ponder.