On March 20, 1919, the American Petroleum Institute (API) was founded in New York City to represent U.S. oil and gas producers, refiners, and pipelines. Its mission was to standardize petroleum measurement and practices, helping the young industry operate safely and efficiently.
API's early efforts included creating standards for barrel volume, refining processes, and pipeline construction. By 1920, API membership represented over 90% of U.S. oil production, making it a powerful force shaping both industry policy and national energy infrastructure.
