The National Security Agency (NSA) is a merger of the National Bureau of Investigation (NBI) which was responsible for covert and overt security investigations, whilst the Executive Action Bureau (EAB) was responsible for carrying out clandestine activities for the Executives.
In the early 1970's, during the administration of President Tubman, similar function to that of the EAB was carried out by the National Intelligence Service (NISS), but on the highest national level. Conversely, the NISS was dissolved following the death of President Tubman and the subsequent taking over of power by President Williams R. Tolbert, Jr., leaving the EAB at the time as the only clandestine agency.
On May 20, 1974, an act repealing sub-chapter D of Chapter 1, Part 1 and subchapter B of Chapter 22, Part II of the Executive Law in Relation to the EAB and the NBI, and creating the NSA was approved. The NSA was left as the only agency solely responsible for gathering national security intelligence, but having to conduct special investigations, whenever the need arises. Later, on August 30, 1974, the Act creating the National Security Agency (NSA) was published by the Ministry of Foreign Affairs in Monrovia, Liberia.