Pure Food and Drug Act
The 1906 Act paved the way for the eventual creation of the Food and Drug Administration (FDA) and is generally considered to be that agency's founding date, though the agency existed before the law was passed and was not named FDA until later. "While the Food and Drug act remains a foundational law of the FDA mission, it's not the law that created the FDA. [Initially,] the Bureau of Chemistry (the precursor to the FDA) regulated food safety. In 1927, the Bureau was reorganized into the Food, Drug, and Insecticide Administration and the Bureau of Chemistry and Soils. The FDIA was renamed the FDA in 1930."
Reference Daily Intake
The Food and Nutrition Board subsequently revised the RDAs every five to ten years. In 1973, the FDA introduced regulations to specify the format of nutrition labels when present, although the inclusion of such labels was largely voluntary, only being required if nutrition claims were made or if nutritional supplements were added to the food. The nutrition labels were to include percent U.S. RDA based on the 1968 RDAs in effect at the time. The RDAs continued to be updated (in 1974, 1980 and 1989) but the values specified for nutrition labelling remained unchanged.