Question

According to the 1970s census, where did enslaved people live within the United States

Answer 1

According to the 1790 census, enslaved people lived in the following states:

South Carolina (42% of the state's population)
Virginia (39%)
Georgia (35%)
Maryland (32%)
North Carolina (26%)
Delaware (15%)
Connecticut (6%)
New Jersey (6%)
New York (6%)
Rhode Island (1%)
Pennsylvania (0.8%)
New Hampshire (0.1%)
Massachusetts (no slaves - 0%)

Answer 2

The South mostly.
Small portion of the North
Only in the far West