1. In 1846, the Bear Flag Revolt began in Sonoma, California. A group of American settlers declared California an independent republic from Mexico and raised a crude flag featuring a grizzly bear with a star and the words "California Republic."

2. In 1876, the first railroad bridge across the San Francisco Bay was completed. The Oakland Long Wharf and Pier became the western terminus of the transcontinental railroad.

3. In 1913, the Los Angeles Aqueduct was completed. The 233-mile long engineering marvel brought water from the Owens Valley to Los Angeles, allowing the city to grow into a major metropolis.

4. In 1948, President Harry Truman signed the Displaced Persons Act, allowing refugees from Europe to enter the United States. Many of these refugees settled in California, particularly in the San Francisco Bay Area.

5. In 2015, the United States Supreme Court legalized same-sex marriage nationwide, including in California. The landmark decision came after a long history of activism and legal battles in the state, including the 2008 Proposition 8 ballot measure that banned same-sex marriage and was later overturned by the courts.