And at the very moment The British were supposedly fighting slavery, they would stop American ships on the high seas and enslave our sailors to serve on their ships.
I'm not sure the practice of capturing and pressing sailors into serving on ships is the same thing as true slavery. In slavery, the slaves are not only held involuntarily, but they became chattel property, to be bought and sold by their "owners". I don't think this was typically the case for impressment. I'd be happy to be proved wrong if someone has some reliable references.