Californians have long been aware of their rich petroleum deposits. The first well was drilled in 1865, and since then, “Black Gold” has become the dominant fuel of 20th century civilization. Early heavy-gravity oil production was used for oil-burning locomotives and ships. The invention of the internal combustion engine provided new uses for previously unusable petroleum by-products. Another oil product was asphalt, essential for the construction of more roads for the new “highway locomotive.”
Southern California became the center for the state's oil production. Production increased from 40,000 barrels in 1880 to over 260 million per year during the peak of the 1920s oil boom. Between 1903 and 1936, the Golden State was the country's leading oil producer, with many California companies dominating the market.