What is the history of Earth Day? Earth Day was born in the wake of a disaster. In 1969 in . 6 miles off the shore of Santa Barbara, California sat Union Oil’s platform A. It was situated atop of the Dos Cuadras Offshore Oil Field. On January 28, 1969 platform A was drilling a fifth well from their location. When they struck their final depth there was an explosion of natural gas. Due to inadequate piping, this blow-out caused what was at the time the largest oil spill in US history.