Based on the paper, in the United State, intelligence services are provided by 16 government-owned intelligence agencies. All these sixteen intelligence agencies form the famous the United States Intelligence Community. All these agencies are ascribed with the duties of conducting several matters related to foreign relations and most importantly working separately as well as jointly to ensure the protection of the national security. For ensuring national security the U.S. Intelligence Community has to conduct a variety of activities. For instance, the agencies that are included in the Intelligence Community have to collect necessary domestic as well as foreign informations, use those informations for producing domestic and foreign intelligence, provide significant contribution to military planning and perform the role of spies to gathers necessary informations regarding the movements and strategies of the enemies of the nation. To build a good understanding of the United States Intelligence, it is not sufficient enough to look at its present structure and current activities. The Current structure and the span of the activities of the U.S. Intelligence community can best be understood by examining its evolution since the starting of the Second World War. Since the time of the Second World War, the U.S. intelligence system has gone through several dramatic changes. It would be quite interesting to examine how the U.S. Intelligence has evolved into its current structure with the passage of time. If one compares the intelligence system of U.S. during the period of the Second World War with that which exists after the 9/11 and Iraq events, it can easily be found that during this long time period, the intelligence system of U.S. has changed dramatically. But the important point to be considered here is that all of these changes have not come at once.