As the Eisenhower administration began to commit the United States to an anti-communist advisory role in Vietnam in the 1950s, the Army Map Service (AMS) discovered that its comprehensive maps of Vietnam had become dated and showed signs of inaccuracy. Unfortunately, few sources existed to revise the existing topographic maps and aeronautical charts. AMS addressed the problem in 1956 by entering into a cooperative mapping agreement with the newly formed Republic of South Vietnam.
American and Vietnamese cartographers and surveyors conducted topographic and geodetic surveys and took countless aerial photographs to build a knowledge base. The AMS – a heritage organization of the National Geospatial-Intelligence Agency – then used the new data to complete a revision of its large- and medium-scale maps in advance of the U.S.’s commitment of combat forces in Vietnam.