The admission of California as a state posed a problem for Congress because it upset the balance between free and slave states in the Senate. Prior to California's admission, there were 15 slave states and 15 free states in the Union. This balance allowed Congress to maintain a fragile equilibrium between the interests of slaveholding states and non-slaveholding states. However, California's admission as a free state threatened to upset this balance and potentially give free states greater representation in Congress. This led to heated debates and negotiations over the status of slavery in the territories, ultimately resulting in the Compromise of 1850.
