During World War II Warren Hunter served as a civilian cartographer for U. S. Army Corps of Engineers at Fort Sam Houston in San Antonio. Later he transferred to the Army’s Map Service, where he headed up the labeling and scaling section.
In 1943, he went to Washington, D.C., to the World Map Indices Section. Shortly thereafter, he was promoted to liaison officer between San Antonio and the map headquarters in Washington. Near the end of the war, he was transferred to the U. S. Office of Strategic Services (OSS), a secretive organization and predecessor to the CIA. He claimed he had nightmares the entire time he was with the OSS!