 Blackstone River Valley was one of the most popular industrialized riverways early on in American history. Actually, fun story. I have one of my longtime best friends. His wife is a marine biologist. Oh, cool. And she travels. They live in, like, upstate Massachusetts, but they travel to the Blackstone River to take samples for, like, fresh water. Really? Because it's the most polluted water system in the United States. Wow.