The vast western lands acquired in the Mexican War set off a new controversy over the rights of slavery in the territories. The South wanted access to the new territory and claimed the right to introduce slave labor. After extended and angry debate in Congress, the three great sectional leaders, Daniel Webster for the East, Henry Clay for the West, and John C. Calhoun for the South, forged the Compromise of 1850. California was admitted to the Union as a free state, and the question of slavery in the remaining territory of New Mexico was deferred. The slave trade was abolished in the District of Columbia, but the South would enjoy the protection of a new and stringent Fugitive Slave Act. Federal marshals helping slave owners pursue fugitives could call on any citizen to assist in the recapture. New federal commissioners rather than courts of law heard fugitive slave cases. The new law allowed the slave power, with the aid of the federal government, to ride roughshod over personal liberty laws in the free states. Antislavery activists turned fugitive cases into protest movements. Free black communities mobilized vigilance committees and Underground Railroad networks. In some cases, they rescued fugitives and spirited them to freedom. A measure designed to end slavery agitation only further fanned the flames as the Fugitive Slave Act brought the reality of slavery home to many northern communities.