Slavery: Why Was It Concentrated in the South of the United States

Where the Slaves Were in 1860

Source: "These Maps Reveal How Slavery Expanded Across the United States"

I quote from Wikipedia:

(I)n the American South an entire civilization was based the "King Cotton". As the chief crop, the southern part of United States prospered thanks to its slavery dependent economy. Over the centuries cotton became a staple crop in American agriculture. 

Cotton is grown where it is economically productive to grow cotton. Even today, as the next map shows, cotton is primarily grown in the United States in the South, where the climate and other conditions favor cotton farming.

"Map 07-M189 Acres of Upland Cotton Harvested as Percent of Harvested Cropland Acreage, U.S., 2007." by National Agricultural Statistical Service, United States Department of Agriculture - http://www.agcensus.usda.gov/Publications/2007/Online_Highlights/Ag_Atlas_Maps/Crops_and_Plants/. Licensed under Public Domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Map_07-M189_Acres_of_Upland_Cotton_Harvested_as_Percent_of_Harvested_Cropland_Acreage,_U.S.,_2007..gif#/media/File:Map_07-M189_Acres_of_Upland_Cotton_Harvested_as_Percent_of_Harvested_Cropland_Acreage,_U.S.,_2007..gif

In the early 19th century -- when cotton was manufactured into cloth not where it was grown but in the north-eastern, industrial states and in Great Britain -- it was important that American cotton be grown not only were it grew best, but also where it could easily be shipped to market. Thus the Mississippi served as a trade route for shipment of the cotton bales, as did the Atlantic ports.

Slaves were crucial to the successful growth of cotton on the southern plantations, but free men were more successful in the small farms and industries of the northern United States. Thus, the abolition movement could be successful and slavery had been abolished in these northern states prior to 1860.

I note that the production of cotton fiber was greatly facilitated by the invention of the cotton gin in the last decade of the 18th century. The cotton gin automated the previously very labor intensive job of eliminating the seeds from the fiber. and thus made cotton fiber much less costly to produce.

A key industry in the British Industrial Revolution (as well as the development of the mills in the northern United States) was the manufacture of cotton cloth, which replaced wool cloth as the major output of the mills. I quote again from Wikipedia:

By the turn of the 19th century, imported American cotton had replaced wool in the North West of England, though wool remained the chief textile in Yorkshire. Textiles have been identified as the catalyst in technological change in this period. The application of steam power stimulated the demand for coal; the demand for machinery and rails stimulated the iron industry; and the demand for transportation to move raw material in and finished products out stimulated the growth of the canal system, and (after 1830) the railway system...... 

Apart from coal and iron, most raw materials had to be imported, so that in the 1830s the main imports were, in order, raw cotton (from the American South), sugar (from the West Indies), wool, silk, tea (from China), timber (from Canada), wine, flax, hides and tallow. By 1900, the UK's global share soared to 22.8% of total imports. 

Slavery in Maryland -- The Douglass Connection

I got interested in this topic because I am reading My Bondage and My Freedom,by Frederick Douglass (1818-1895). He was born and lived his early life as a slave on the Eastern Shore of Maryland, and was consumed in those years by the desire to escape from slavery via the free states of Delaware or Pennsylvania.

Quoting from "Agriculture and Labor in Maryland":

Throughout the 17th and 18th centuries, Maryland was a tobacco growing colony. Gradually, the labor force transitioned from indentured servants to enslaved Africans, and by the Revolutionary War they comprised the large majority of agricultural labor. During the 18th and into the 19th centuries, however, things began to change. Tobacco had been harsh on Maryland soils, and planters in the northern and eastern shore counties began to replace it with wheat, which required less labor. This had an effect on enslaved labor, and planters began to find ways to get rid of their labor force. In the southern counties, however, tobacco was still a major cash crop, and was part of a diversified agricultural production. Because of this, the slave population remained steady leading to the Civil War. 

For Maryland planters in the northern and eastern counties, the move to less intensive crops meant that they had to reduce their slaveholdings. Maintaining a large workforce was expensive: food, shelter, and clothing had to be provided for a number of laborers. Wheat, however, only required large workforces twice a year, for planting and harvest, unlike tobacco which required labor for most of the year. In order to reduce their slaveholdings, planters used a number of strategies. Some freed their slaves, either immediately or through a system called term slavery, where African Americans were enslaved until a certain age and then freed. Others rented their slaves to other plantations or into the growing industrial sector or to urban areas such as Baltimore. Finally, many sold their remaining slaves, either to the Southern Maryland counties or to the Southern states, where the demand for slave labor was growing. All of these approaches had dramatic effects on the stability of African American families. It also meant that Maryland had the highest percentage of free blacks out of any slaveholding state in the United States heading into the Civil War.

Slavery was of course introduced into Maryland early in its history and was an integral part of the plantation system for the production of tobacco in Maryland for export to Great Britain. However, there were relatively strong abolition forces in Maryland in the 19th century and a fairly active underground railroad helped people escaping slavery move through the state. By 1860, as the following map shows, there was a significant divide in the state, with slavery concentrated in the southern parts of the state (the Chesapeake Bay region). So too, abolitionists had been more common in the north of the state, supporters of slavery among the whites in the southern parts.

Slaves as a Percentage of Each Maryland County's 1860 Population

Source

Importation of slaves into the United States was abolished under law in 1808. However, interstate sales of slaves continued to be legal in the United States until the 13th amendment to the Constitution in 1865.

Quoting from "The Domestic Slave Trade":

The export trade from Delaware, Maryland, and Virginia was very well established by the 1780s........The interregional movement of the enslaved population was made up of two elements. The substantial majority - from 60 to 70 percent (or 1.2 million people) - migrated by the long-distance domestic slave trade, while the rest were part of planter migrations. In the latter case, planters looking for new opportunities moved all or most of their slaves together to work new western land. 

By the 1790s, Maryland, Delaware, and Virginia had become the main exporting areas, the bulk of their "shipments" going to Georgia, Tennessee, Kentucky, the Carolinas, and the sugar-planting regions of Louisiana. But by the 1820s the Carolinas and Kentucky were exporting more people than they were importing. 

Thirty years later, Tennessee, Missouri, Georgia and Alabama had joined the ranks of net exporters. From 1760 until the Civil War, the number of men, women, and children traded to the South and West increased substantially during each decade, with the exception of the 1840s when numbers slackened.

Thus I think that the booming market for cotton was leading to a great demand for slaves in the deep south, while the northern states did not need nor want slaves and abolished slavery. Maryland, was split with the northern part of the state having relatively few slaves but the south having more, notably in its continuing tobacco plantation system.