Why didn't The Missouri Compromise line not apply to California and statehood?

The Missouri Compromise line, established in 1820, aimed to balance the admission of slave and free states but did not extend to California because it was not yet a state during the compromise's creation. By the time California sought statehood in 1850, the debate over slavery had intensified, and the Gold Rush had led to a significant population influx, prompting California to apply for statehood as a free state without regard to the original compromise. Additionally, the growing sectional tensions made the application of the Missouri Compromise increasingly untenable.