Final answer:
The California Gold Rush in 1849, sparked by the discovery of gold at Sutter's Mill, resulted in a dramatic influx of diverse settlers and a shift in power dynamics - thereby transforming a society initially dominated by the landholding elite. This period also witnessed significant social changes linked to rapid Anglo-American expansion and California's entry into the Union in 1850.
Step-by-step explanation:
The significant transformation in California's society, dominated by a landholding elite, occured primarily due to the California Gold Rush in 1849. The discovery of gold at Sutter's Mill in Coloma, California stirred an exorbitant inflow of prospectors and settlers in search of new fortune. This influx not only diversified the societal composition with a mix of gold miners, businessmen, saloonkeepers and others, but also changed the power dynamics, moving it away from the landholding elite. Concurrently, the expansion of Anglo-American settlers resulted in the socio-political marginalisation of the original Hispanic populations. Furthermore, the change was fueled by the state's readiness to enter the Union in 1850, which brought about new political structures and challenges like the slavery debate.
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