The Air Pollution Control Act was the culmination of much research done on fuel emissions by the federal government in the 1930s and 1940s. Additional legislation was passed in 1963 to better fully define air quality criteria and give more power in defining what air quality was to the Secretary of Health, Education, and Welfare. This additional legislation would provide grants to both local and state agencies. A replacement, the Clean Air Act (United States) (CAA), was enacted to replace the Air Pollution Control Act of 1955. A decade later the Motor Vehicle Air Pollution Control Act was enacted to focus more specifically on automotive emission standards. A mere two years later, the Federal Air Quality Act was established to define "air quality control regions" scientifically based on topographical and meteorological facets of air pollution.