Oh, now...what does premise and logic have to do with democratic press releases?.....
Slavery was legal in Massachusetts up to 1783 it looks like.
http://www.slavenorth.com/massemancip.htm
You hit the nail on the head, Doug.
Even after slavery was abolished in the New England states (particularly in Massachusetts, Connecticut, and Rhode Island), businessmen in those states continued prospering from the slave trade, importing slaves to the southern states where such was still legal.
The wealth of many New England families was based upon dealing with this particular, uh, commodity.
Slavery is, and always has been, an abomination on mankind, but there is little difference between those who have (or had) humans as personal property, and those who provide (or provided) humans as personal property.