The Bureau of Secret Intelligence was founded in 1916. The U.S. Department of State's Bureau of Secret Intelligence, later known as the Office of Security (SY) and now as the U.S. Diplomatic Security Service, was also known as U-1, an off-the-books adjunct to the Division of Information [1].
The origins of the U.S. State Department's Diplomatic Security Service (DSS) goes back to 1916 with a handful of agents assigned special duties directly by the Secretary of State (SECSTATE), Robert Lansing. Lansing, who used MID and Secret Service agents to obtain secret information, longed for direct control over his own agents; therefore, in 1916 he created a Bureau of Secret Intelligence.[2]
Headed by a Chief Special Agent, who was also called Special Assistant to the Secretary, these agents worked in Washington, D.C., and New York City. This group of agents would sometimes be referred to as the office of the Chief Special Agent. They were operated with private funds from the Secretary's office. Conducting sensitive investigations, they focused mainly on foreign agents and their activities in the United States.
The assumption is that the name "Office of the Chief Special Agent," which was sometimes used in 1916, and to this day by various information portals to include the Department of State's website, is used to downplay the bureau's original mission.