(Photo: ThinkStock)

California just had its birthday: On September 9, 1850, it became the 31st state in the Union. Let's celebrate with 19 facts about the Golden State.

1. The 1848 Treaty of Guadalupe Hidalgo ended the Mexican-American War. The U.S. paid Mexico $15 million for war damages. In turn, Mexico ceded nearly half of its territory, including California, Arizona, New Mexico, Texas and parts of Colorado, Nevada and Utah.

2. California was originally known as the Bear State. As California boomed—and the bear population was wiped out—it became the Golden State.

3. The grizzly bear on California's current state flag is a tribute to Monarch, the last wild California grizzly bear. In 1899, newspaper magnate William Randolph Hearst paid a reporter named Allen Kelley to capture the animal. Monarch was sent to San Francisco, where he lived at Woodward's Garden and then Golden Gate Park. He was a star attraction until his death in 1911.

(Photo: Wikimedia Commons)

4. But the original Bear Flag had nothing to do with Monarch. It dates back to 1846, two years before the Treaty of Guadalupe Hidalgo. A group of Americans who'd settled in California, which was then part of Mexico, feared they'd be expelled. They invaded the Mexican outpost at Sonoma and captured the retired general Mariano Vallejo. A few days later they raised the first Bear Flag and called the land the California Republic.

5. The California Republic only existed for 26 days. U.S. Army Major John C. Frémont soon replaced the Bear Flag with the U.S. flag, which takes us back to the beginning of this post and the Mexican-American War.

6. And who designed the original flag? William Todd, nephew of Mary Todd Lincoln. It's a small historical world.

(Architect of the Capitol / Wikimedia Commons)

7. The one-word state motto, "Eureka," hearkens back to the exciting days of the Gold Rush. But it doesn't include an exclamation point. The first "Eureka!" is attributed to the Greek scholar Archimedes. According to legend, he had an epiphany as he stepped into a bathtub and watched the water level rise—he realized that the volume of the displaced water was equal to the volume of the foot he'd submerged. And then he ran out of the room to tell others about his discovery ... while he was completely naked. (More on whether that ever actually happened here.)

8. California's most famous for its Gold Rush in 1849, but it also had a Silver Rush in the Calico Mountains from 1881 to 1896. By 1904, Calico was a ghost town.

9. In 2013, the states of California and New York tied for the fourth-highest average credit score in the U.S.—653. (Minnesota was the victor, with an average score of 658.)

Click here for the next 10 fascinating factoids about California.



(Photo: Alexis Fam Photography / Flickr)

10. The first step to getting a star on the Hollywood Walk of Fame: Work in entertainment. The second: Pay a $30,000 nomination fee. Living celebrities are required to appear at their star's unveiling. (Barbra Streisand is the only person who got away with missing the event.) All of the Munchkins from The Wizard of Oz—122 adults and 12 children—share one star.

11. California is the only state that's hosted both the Summer and Winter Olympics.

12. More of the U.S. athletes competing in the 2012 London Olympics came from California than from any other state. But take that with a grain of salt—one out of every eight Americans is from California.

13. The fortune cookie was inspired by the Japanese cookie o-mikuji and invented in California.

14. Except for Alaska, California contains more forest land than any other state.

15. Despite living in Los Angeles for 78 years, writer Ray Bradbury never learned to drive.

(Photo: Wikimedia Commons)

16. The mineral benitoite can be found in California, Japan, and Arkansas, but only San Benito County, Calif., has it in gemstone-quality deposits. The California State Gem Mine in Coalinga allows the public to dig and take home a quart-sized bag of treasure.

17. I can haz state recognition? In 1973, the saber-tooth cat, Smilodon californicus, became California's state fossil. A year earlier, Assemblyman W. Craig Biddle had nominated the cockroach-like trilobite for the honor. Nearly 2,000 museum curators and fossil experts backed him, but the bill never made it to a vote. A year later, the saber-tooth cat made it to the floor and passed. The one no-vote? Senator W. Craig Biddle.

18. Thousands of U.S. banks failed after the 1929 stock market crash—by 1933, only 11,000 were left. All of San Francisco's banks survived.

19. The highest point in the contiguous U.S., 14,494-foot Mt. Whitney, is only 76 miles from the lowest point in the U.S., Death Valley. They're both in Cali— well, you know.