The Chemical Corps is a branch of the United States Army responsible for defending against chemical, biological, radiological, and nuclear (CBRN) threats. Established during World War I in 1918 as the Chemical Warfare Service, it was created in response to the widespread use of chemical weapons on the battlefield. The Corps played a pivotal role throughout the 20th century, developing protective equipment, conducting research, and training soldiers in CBRN defense. Today, the Chemical Corps continues to ensure the Army’s readiness to operate in contaminated environments and to counter CBRN threats worldwide.