DOD
DOD/NGA/GSD
The US geospatial intelligence effort began in 1803 when President Thomas Jefferson sent the Army?s Lewis and Clark expedition to explore and map the recently acquired Louisiana Territory. As the Army, assisted by its contract civilian scientists, supported the country?s westward expansion, the Navy similarly began reaching out across the oceans. This maritime expansion, coupled with the Navy's desire not to have to rely on British orcommercial charts, led to the establishment of the Navy Depot of Charts and Instruments in 1830. US mapping and charting efforts remained relatively unchanged until World War I, when aerial photography became a major contributor to battlefield intelligence. Using stereo viewers, photo interpreters reviewed thousands of images. Many of these were of the same target at different angles and times, giving rise to what became modern imagery analysis and mapmaking. After the war, as airplane capacity and range improved, the need for charts grew. The Army Air Corps established its Map Unit, which was renamed the Aeronautical Chart Plant in 1943 and began work in St. Louis, MO. With America?s entry into World War II, map service requirements greatly expanded. Summary provided by http://www.nga.mil/portal/site/nga01/