1. In 1847, the first official state elections were held in California. This marked the beginning of California's journey towards statehood, which it achieved in 1850.

2. In 1901, the first oil gusher in California was discovered in the town of Petrolia. This sparked an oil boom that would transform the state's economy and lead to the creation of major cities like Los Angeles.

3. In 1920, the League of Women Voters was founded in California. This organization was instrumental in the fight for women's suffrage and continues to promote voter education and engagement to this day.

4. In 1946, the first computer was demonstrated in California by the Electronic Numerical Integrator and Computer (ENIAC) team at the University of Pennsylvania. This event marked the beginning of the computer age and set the stage for California's emergence as a leader in the technology industry.

5. In 1969, the Santa Barbara oil spill occurred, which remains one of the worst environmental disasters in American history. The spill, which was caused by a blowout at an offshore oil rig, led to the deaths of thousands of marine animals and served as a wake-up call for the need to protect California's natural resources.