A 2002 Census publication tracks the growth of the slave population in the South, 1790 – 1860. The chart shows the growth of the slave population in the South. Importation of slaves was banned in 1808. The slave population grew from 1790 to 1860 – 70 years — by an average compound rate of 2.4% a year. Contrast that with the average compound rate of growth of the U.S. population between 1945 and 2000 – 1.3%.
In 1860, 66% of the North’s Black population was free; only 6% of the Black population in the South was free. The South accounted for 91% of the Black population in the U.S. in 1790, and 92% in 1860.
Now look at the northern migration of Blacks, which took off in the early 20th Century. These charts show the percentage of population that was Black. The decline in the percentage of blacks in the Mississippi population reflects southern out- migration. The rise in the percentage of Blacks in Illinois reflects northern in-migration. In 1900, the South accounted for 89% of the Black population; in 1990, only 52%.