The logo of this group was an open eye with the slogan "We never sleep.
One member of this group, Charlie Siringo, wrote the book Two Evil Isms comparing this group to anarchism. Another member, James McParland, used the alias "James McKenna" when working for Franklin B. Gowen. Dashiell Hammett worked for this group and used his experiences when writing about the Continental Op. The logo of this group was an open eye with the slogan "We never sleep." One member infiltrated the organization known as the Molly Maguires. Its namesake and founder foiled an assassination plot against Abraham Lincoln prior to being inaugurated, and members of this group were hired to track Jesse James and the Reno Gang. For 10 points, name this detective agency founded in 1850, whose employees frequently worked as strikebreakers.
One member of this group, Charlie Siringo, wrote the book Two Evil Isms comparing this group to anarchism.
Pinkerton National Detective Agency [accept Pinkertons or anything with the word Pinkerton in it]