1. In 1769, Spanish explorer Gaspar de Portolá established the first land expedition to California on August 15. This expedition paved the way for the eventual settlement of the state by both Spanish and Mexican settlers.

2. On August 15, 1846, the Bear Flag Revolt began in what is now Sonoma County. American settlers in California, dissatisfied with Mexican rule, seized control of the region and declared an independent republic. This event is considered a key moment in the fight for California statehood.

3. August 15, 1914, marked the opening of the Panama Canal, which had a profound impact on California's economy and trade. The canal provided a shortcut for ships traveling between the Atlantic and Pacific Oceans, making it easier for goods and people to travel to and from California.

4. In 1969, the Woodstock music festival took place from August 15-17. Although the event took place in upstate New York, it had a significant impact on California's counterculture movement and music scene.

5. On August 15, 1971, the first IBM personal computer was released. This computer revolutionized the way people work and communicate, including in California's technology industry, which continues to be a major contributor to the state's economy.