A Northern Emancipation Question (Essay One)

I recently spent time learning about Matthew Fontaine Maury, the famous American scientist and naval officer from Virginia. In 1852 he wrote an essay with the following passage:

“The negroes from the Middle and the New-England states, who, under the emancipation laws of those states, were forced into the markets of Va. and other southern states, did not thereby become more of slaves than they were before. There was a transfer of the place of servitude — that was all.”

My bias with this type of statement is to believe it. Money would have tended to drive behavior when it came to “emancipation”. Was emancipation in the North a 19th century virtue signal? Could it be that these Northern slaves were sold to people in the South?

I did a little more research and asked some people I respect, and it seems there is no readily available answer. I enjoy looking at census data and have written some on the 1860 through 1880 censuses. Could census data provide the answer? This will be the first of several essays of my attempt to answer the following question:

Were large numbers of slaves from Northern states sold to people in Southern states instead of being set free?

This initial essay does not answer the question, but here are some facts that come from comparing the 1790 and 1800 censuses. The United States population grew from 3.9 million to 5.3 million or a 36% growth rate. The slave population grew at a rate of 29% overall. The free not white population grew by 76% or by a total of 45,000 people. In what would become the free states, the number of slaves reduced by 10% and free not white increased by 74%. In the slave states, slave numbers increased by 31% and free not white increased 77%.

These early censuses do not supply immigration numbers, so it is hard to tell the impact of immigration on growth. Also, the census does not provide data on the number of slaves imported. More in future essays.