Like, the Pinkerton Detective Agency? They were founded in the 1850s in Chicago by a Scotsman. They worked for the U.S. government quelling labor activity during the 1800s, until 1897, I believe, when after a particularly violent encounter, Congress quit funding them.
They went on to bully, arrest and outright kill union members and organizers during various clashes during the early 1900s. I believe they were present at Blair Mountain, the Steel Strike, etc. Shortly, they worked for Andrew Carnegie at one point.
https://pinkerton.com/our-story/history
Here's their website. They're owned by Securitas.