On March 23, 1921, crews began drilling the Alamitos No. 1 well on Signal Hill, California. When the well struck oil later that year, it launched one of Southern California's largest petroleum booms, transforming Long Beach into a major oil-producing region.
Signal Hill alone produced over 10 million barrels in its first year, while Long Beach quickly became home to more than 500 active wells, supporting local refineries and fueling rapid urban growth in the Golden State.
