Spying has been part of American history since the revolution. Nathan Hale was spying on the British when he was caught on Long Island and subsequently hanged. Major Andre was attempting to link up with Benedict Arnold for the betrayal of West Point when he was caught. He was hanged as a spy on Washington`s explicit orders, probably due to the Hale case.
During World War II, American spies were run through the Office of Strategic Services (OSS) under the supervision of Bill Donovan. Following the war, all foreign spying was given to the Central Intelligence Agency, which is forbidden by law from conducting operations within the country.