1. On January 29, 1847, during the Mexican-American War, the Battle of La Mesa was fought just outside of present-day Los Angeles. The battle resulted in a decisive victory for the United States.

2. In 1861, the first Yosemite Grant was signed by President Abraham Lincoln, protecting the Yosemite Valley and Mariposa Grove from private development and declaring them public land. This was the first time in history that land had been set aside for preservation purposes.

3. On January 29, 1920, the Oakland Tribune published its first edition. The newspaper went on to become one of the largest in California and was known for its investigative reporting and coverage of local sports teams.

4. In 1947, the first commercial television station in California, KTLA, began broadcasting in Los Angeles. The station has been credited with many "firsts," including the first to air a live entertainment show and the first to broadcast in color.

5. On January 29, 1986, the Space Shuttle Challenger disaster occurred. The shuttle broke apart 73 seconds into its flight, killing all seven crew members, including teacher Christa McAuliffe. The tragedy shook the nation and had a profound impact on the future of the space program.