The number of black slaves rose from 3.3 million to 3.95 million, and those who extended this population growth forward declared that slaves would one day outnumber free persons throughout the South. The free black population, nationwide, increased to about 470,000 persons.

The census also revealed that the black population was moving steadily west and south. As recently as 1820, the great majority of slaves had been in the Tidewater states of Virginia, Maryland, and North and South Carolina, but Louisiana, Mississippi, and Texas were the places where the slave population was growing the most.