How did henry clay propose to admit california to the union without upsetting the balance between slave states and free states

Prior to the Civil War, the issue of slavery was considered one of the main problems facing the Union. This was because some states in the nation allowed slavery, while some others were "free states." The numbers of each side needed to remain equal in order for a balance of power to be maintained. The addition of any other territory threatened such an order.

California was such a state. It had grown tremendously due to the gold rush, and it now petitioned to join the Union as a free state. A compromise was presented by senator Henry Clay. He proposed to accept California as a free state. However, in order to pacify politicians from slave states, he also proposed the Fugitive Slave Act. The act required citizens (including those living in free states) to assist in the recovery of fugitive slaves. This compromise was known as the Compromise of 1850.