California was applying admitted to Union as a free state in 1849, and this upset the balance of power between the North and the South. As a result the Southern Democrats advocated for a compromise to restore the balance of power
Tensions between the North and South, regarding the newly annexed territories in the west, were medicated when they came to a compromise that gave the south a federal assurance that the government would not restrict slavery in Utah or New Mexico. California was admitted as a free state, and the slave trade in the capital was put at a halt.
Additionally, another clause in the compromise was an improved Fugitive Slave law that allowed the South to more adequate capture escaped slaves in the north