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Mapping the Americas

Mapping the Americas: Inter American Geodetic Survey (IAGS)

Copyright NGA Historic Research Center
Copyright NGA Historic Research Center

Little known to most Americans today, the Inter American Geodetic Survey (IAGS) successfully assisted Latin American countries in professionally mapping their own extensive territories. After World War II revealed a lack of accurate maps of the Western Hemisphere, IAGS staff proposed in 1946 that they assist Central and South American countries by providing technical support in all phases of their mapping programs.

Copyright NGA Historic Research Center
Copyright NGA Historic Research Center


Initially managed by the Army Map Service (AMS) and later by an NGA predecessor agency, the Defense Mapping Agency (DMA), IAGS operated under diplomatic agreements. Each agreement was negotiated by the State Department with the various Latin American countries. These alliances laid the groundwork for an American staff to work alongside Hispanic technicians and students to map their own countries.

The primary mission of IAGS was to make the countries cartographically self-sufficient. In return for its support, the United States gained access to all originally gathered data. It also benefitted from building strong relationships with various governments and national leaders.

Copyright NGA Historic Research Center
Copyright NGA Historic Research Center


Between 1946 and 1952, Americans trained local nationals on the job, teaching them to create maps of their own country. As the need for more advanced training became apparent, AMS established the IAGS Cartographic School. Founded in 1952 and located near IAGS headquarters in the Panama Canal Zone, the school had two specific objectives. First, the school staff standardized teaching techniques as well as procedures and specifications for mapping and charting. The second goal was to help develop self-sufficient national cartographic agencies in Latin America.

All instruction was offered in Spanish. The courses ran from eight to sixteen weeks, and over time, the curriculum came to offer special instruction in basic photogrammetry, advanced photogrammetry, cartographic drafting, triangulation and supplemental control, geodetic computation, astronomy, basic vertical control, field classification, and map compilation.

Copyright NGA Historic Research Center
Copyright NGA Historic Research Center


The 937th Engineer Company supported field operations by flying reconnaissance and transporting supplies and people to work sites. Its work proved invaluable to the IAGS mission. Light planes enabled IAGS surveyors to spot the easiest routes through rough terrain and pick the best sites for survey stations. Helicopters transported men and gear, which saved days of hacking through dense jungle or carefully climbing up icy mountains. Airlifts of food, water, and other supplies cut down on exhausting and time-consuming packing trips. 

Illustrations suggest the 937th Engineer Company also assisted with many rescues and humanitarian operations over the years, from hurricane, flood, and earthquake relief to transporting accident victims. When locations were too remote to quickly get the necessary help, the 937th Engineer Company expertly flew essential IAGS missions.

Copyright NGA Historic Research Center
Copyright NGA Historic Research Center


IAGS teams climbed, paddled, and hacked their way across most of a hemisphere. The dedicated men and women produced remarkable work despite many challenges. Their efforts led to the standardization of maps, acquisition of new geographic data, development of numerous cartographic agencies, and education of new cartographers, while generating international goodwill across Central and South America.

During the 1970s, pressure slowly mounted to end IAGS. By the 1980s, a combination of budgetary reductions and the Panama Canal Treaty of 1977 triggered the relocation of IAGS headquarters to Fort Sam Houston in San Antonio, Texas. Nine years later IAGS was disestablished. 

Although incidents resulting in injury and death were rare over the tenure of IAGS, approximately twenty-five IAGS staff members died while serving the mission.

The achievements of IAGS further benefitted Latin America by encouraging economic development. With maps as the key, countries could engage in nation-building activities such as highway construction, river navigation, hydroelectric dams, and oil exploration. Thanks to the IAGS, they knew their countries better than ever.

Copyright NGA Historic Research Center
Copyright NGA Historic Research Center


  • The disc shape of the insignia represents the surface of the benchmark and triangulation station markers used with geodetic surveying.
  • The blue triangle symbolizes survey work.
  • The Engineer Castle indicates that the Army Corps of Engineers was responsible for accomplishing the cartographic work in Latin America.
  • The various colors represent the basic colors of the national flags of the countries in which the IAGS operated.
  • The inscription “Servicio Geodesico Interamericano” is the Spanish translation of the program’s name.
Copyright NGA Historic Research Center
Copyright NGA Historic Research Center


1946 – Establishment of IAGS by President Harry Truman

1950 – The United States entered the Korean War

1952 – Establishment of the Cartographic School at Fort Clayton, Panama Canal Zone

1960 – Cuba became the first country in which surveying was complete

1962Cuban Missile Crisis

1968 – Army Map Service is redesignated the Army Topographic Command

1972 – IAGS becomes a component of DMA

1975 – US pulls troops out of Vietnam

1976 – 1:50,000 topographic scale maps were completed in all Central American nations

1980 – IAGS HQ moves to Fort Sam Houston, TX

1981 – IBM markets the first personal computer

1982 – 4.8 million square mile of topographic maps were published by the IAGS cooperating nations

1989 – DMA IAGS is disestablished under President George H. W. Bush

1996 – The National Imagery and Mapping Agency is established by President Clinton


*Images used are from donations made IAGS veterans to the NGA Archives. All images are government owned.

Associated Document(s)

Mapping the Americas: Inter American Geodetic Survey Booklet
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