Background
In the wake of Pearl Harbor, the President realized that the need for a new form of Central Intelligence with no ties to any other branch of government. He saw the need for an organization that could travel around the world to collect intel on what other nations were doing, in order to advise politicians on what actions they should take involving foreign policy, because of this the CIA was formed. In 1947 President Harry Truman singed the National Security Act which created both the CIA and the NSA.
The National Security Act
The National Security Act was a piece of legislation voted in by Congress in order to provide the country with a new central form of intelligence to help shine light on foreign affairs. This bill created the CIA, the NSA, and the NSC or National Security Council which is made up of a number of political leaders to preside over the CIA and NSA. In this bill it stated that the CIA would be and independent, central agency, overseeing strategic analysis and coordinating clandestine activities abroad. This marked the first peacetime intelligence agency to ever be formed in the United States. This bill however did not link all intelligence under one roof, but rather allowed for each section of the armed forces to have their own intelligence along with the CIA acting as its own body.
Goals of the CIA
The main goal of the CIA was to oversee foreign affairs with nobody looking over their shoulder per say to see what they were doing. One of the main concerns with creating the CIA was that the U.S. was essentially creating an American Gestapo, or an organization that had no one to check their power. This is why the CIA was declared to only deal with foreign affairs and would not allow for the CIA to have any police, subpoena, or law enforcement powers. The CIA was essential during the Cold War times by infiltrating countries under the sphere of influence of the USSR. By doing this we were able to obtain essential information pertaining to the actions that the Soviets were taking, such as the information that Cuba was harbouring nuclear missiles for the USSR which lead to the eventual Cuban Missile Crisis.