"After World War II, the National Security Agency (NSA) established and directed three programs that deliberately targeted American citizens' private communications. Despite ethical and legal concerns, these programs continued through the early 1970s. This intelligence oversight failure, once it was identified, resulted in a thorough U.S. Senate investigation. Out of this investigation came the 1976 document 'NSA Surveillance Affecting Americans,' which led to legal restrictions on the agency and robust intelligence oversight processes to ensure that it continued to adhere to these restrictions. This article will summarize the programs that led to this situation, review the legal decisions that affected these programs, and discuss the impact that is still felt within the NSA today."