What did California's have that Americans including president Polk want?

California had valuable resources and land that Americans, including President James K. Polk, wanted for expansion and economic opportunity. The discovery of gold in 1848 during the Gold Rush heightened interest in California, making it a prime target for settlement and investment. Additionally, Polk's belief in Manifest Destiny fueled the desire to acquire California as part of a broader vision for U.S. territorial growth. This ultimately led to the U.S.-Mexico War and California's eventual annexation.