In 1951, at the height of the Cold War, the U.S. Army Chemical Corps and Ordnance Corps initiated a program to develop a new rocket that could deliver chemical weapons over a large area. The result was the M55 rocket, which was equipped with a unitary warhead filled with sarin or VX—highly toxic nerve agents. The rocket was rushed into production, and tens of thousands were produced from 1959 to 1965.