 Efforts in the U.S. to protect its workforce first began in the 1870s when factories sprang up across the country after the Civil War. Thousands of young, inexperienced workers were being killed or injured by hazardous machinery. Then, in 1914, the earliest predecessor to NIOSH was founded, called the Office of Industrial Hygiene and Sanitation. Industrial hygiene refers to the identification, study, and control of workplace hazards that may cause injury or illness. The Office pioneered scientific field studies of diseases caused by the work environment. Early industrial hygiene efforts focused on protecting workers from mining or machinery-related accidents and cancer-causing chemicals. In World War II, this work expanded to include weapons plants where researchers were instrumental in preventing diseases such as TNT poisoning. So how did the Occupational Safety and Health Act that created NIOSH come to be? After years of public and labor groups demanding safer work, President Lyndon B. Johnson called for Occupational Safety and Health Studies and legislation to relieve this tragic burden on the workforce. His call continued until President Nixon signed the Occupational Safety and Health Act in 1970. The Occupational Safety and Health Act also created a mechanism to conduct research in the field of occupational safety and health, including the psychological factors involved. This work led to innovative methods, techniques, and approaches for addressing occupational safety and health problems. Valuation was done March 10, 1970 at the Sager Glove Corporation in Murray, Kentucky, where researchers study asbestos exposures. Health hazard evaluations continue to this day, helping employees, unions, and employers identify and control hazards in the workplace. NIOSH published the first criteria document. Criteria documents provide the basis for comprehensive occupational safety and health standards. In 1972, NIOSH released criteria for a recommended standard, occupational exposure to asbestos. Asbestos is a natural mineral that requires careful study because it can be useful or harmful. For example, it can be used in fireproofing materials and insulation. However, later studies found that exposure to asbestos dust can cause lung disease or cancer. NIOSH published the first pocket guide to chemical hazards in 1978. As researchers identify and investigate new toxic chemicals, NIOSH routinely updates the guide to make sure users have the most up-to-date information on new and existing workplace hazards. The most recent version of the guide is available in print, online, and through mobile app and gives information on hundreds of chemicals and classes, which help users recognize and control chemical hazards in the workplace. Today, NIOSH is part of the Centers for Disease Control and Prevention and has nearly 2,000 researchers, support staff, and contractors in eight locations across the U.S. NIOSH represents a wide range of disciplines including epidemiology, safety, psychology, engineering, chemistry, statistics, and research translation. Over the past 50 years, NIOSH has expanded its focus in many directions, addressing emerging and complex occupational safety and health issues, such as opioid use and misuse, robotics, aging workers, emerging technologies, health equity, the future of work, and COVID-19.