Brotherhood of Locomotive Engineers and Trainmen
The Brotherhood of Locomotive Engineers and Trainmen (BLET) is a labor union founded in Marshall, Michigan, on 8 May 1863 as the Brotherhood of the Footboard. It was the first permanent trade organization for railroad workers in the US. A year later it was renamed the Brotherhood of Locomotive Engineers (B of LE).
Source: Wikipedia — Brotherhood of Locomotive Engineers and Trainmen (CC BY-SA 4.0)