Checkmate is an agency of the United States Government. It is a branch of Task Force X, and it is a spy agency with a hierarchy revolving around the pieces in the classic board game, Chess, with Kings & Queens being the leaders, the Bishops oversee missions behind the scenes, the Rooks plan the missions, the Knights carry out the missions and the Pawns are the support staff. The colors black and white are also indications of the type of Checkmate agent. Black is operations and white is intelligence. Although the U.S. Army wouldn't allow Slade Wilson to remain in the army because of being so unstable, Checkmate welcomed him as an agent. Also, the superhero known as the Vigilante was a member of the agency as well.
Known Checkmate agents
Checkmate first appeared in Action Comics # 598 (March 1988).