Do you consider 1807 “well into the 1800s?”
That’s when the last slave was legally imported into the USA, with the trade thereafter classified as piracy.
Although we unfortunately had to wait till the reign of the Illinois Butcher to hang one of the pirates.
The Constitution protected slave importation until 1808, and Congress duly passed a law that prohibited it on and after January 1 of that year.
In a word, YES. Furthermore, as you so astutely point out, importation of slaves AFTER 1807 was “classified as piracy.” Sorta like the sale of alcohol after the ratification of the 18th Amendment in 1918 was “classified as illegal.” Therefore it didn’t happen, did it? :-)
My point is that the importation of slaves had become a lucrative market on which many had become dependent, and for a number of years AFTER the ban on “legal importation,” the practice continued, with the traders simply going offshore, and carrying on the practice — illegally. Piracy, indeed.
So you’re going to hang your hat on that? This is like saying, “So what if I’m a crack-whore - I blame my pusher. He made me do it!”