It's long been known by Southern historians that New England's boat builders were slavers while business was good. When the importation of slaves was banned in the early 1800s, New England became abolitionists.
Quote from the article below:
Almost all of colonial America’s slave ships originated in New England.
New England and the African Slave Trade
https://www.choices.edu/resour...slavery_reading1.pdf
Nothing surprises me about Yankee hypocrisy.