For John, BLUF: Let's hope it doesn't come here to Lowell. Nothing to see here; just move along.
Terrorism is not new for the United States. Writing specially for The Tampa Bay Times, Mr Gary R. Mormino gives us "Perspective: Lessons from anarchy, Ybor and the original age of terror".
Terrorism as a tactic goes back over 100 years in the United States.
But, even though the article focuses on Ybor City, just north of Tampa, Florida, it points out that from the late 1800s to the first two decades of the 20th Century, terrorism was a world wide phenomenon.
Terrorism is a tactic, used to achieve certain social, religious or political goals. It was a terrorist event, an assassination, that sparked off World War One.
Regards — Cliff