Sunflower Army Ammunition Plant

The Sunflower Army Ammunition Plant was a smokeless powder and propellant manufacturing facility in De Soto within Johnson County, Kansas. Constructed after the attack on Pearl Harbor pushed the United States into World War II, it was the largest ammunition plant in the world during operation. At the time of operations, the plant was located in northwest unincorporated Johnson County, Kansas, owned by the United States Government, and operated under contract, primarily by Hercules Aerospace Company.

In 2005, the U.S. Army transferred the former plant site to the Sunflower Redevelopment Group; in 2022, over 6,000 acres of the site were annexed into De Soto.