For those who are unfamiliar, the Ho Chi Minh Trail is a logistics system that passes through the Annamese mountain range in central Vietnam and was used to supply manpower and materials to the previous populations. The trail began during the First Indochina War as a primitive trail system through dense, uninhabited jungle and was maintained and used with great success by the National Liberation Front during the Vietnam War. The route passed through neighboring Laos and Cambodia, prohibiting most types of formal intervention against it. According to the US National Security Agency's official history of the war, the Trail system was "one of the greatest military engineering successes of the 20th century".