Railroad Retirement Board
The U.S. Railroad Retirement Board (RRB) is an independent agency in the executive branch of the United States government created in 1935 to administer a social insurance program providing retirement benefits to the country's railroad workers. The RRB serves U.S. railroad workers and their families, and administers retirement, survivor, unemployment, and sickness benefits.
Source: Wikipedia — Railroad Retirement Board (CC BY-SA 4.0)