What did the southern, or free states get in the bargain?

The Compromise of 1850 was a package of five separate bills passed by the United States Congress in September 1850, which defused a four-year political confrontation between slave and free states regarding the status of territories acquired during the Mexican-American War (1846-1848). The compromise, drafted by Whig Senator Henry Clay of Kentucky and brokered by Clay and Democratic Senator Stephen Douglas of Illinois, reduced sectional conflict. Controversy arose over the Fugitive Slave provision. The Compromise was greeted with relief, although each side disliked specific provisions. [citation needed]

Texas surrendered its claim to New Mexico, as well as its claims north of the Missouri Compromise Line. It retained the Texas Panhandle and the federal government took over the state's public debt. California was admitted as a free state with its current boundaries. The South prevented adoption of the Wilmot Proviso that would have outlawed slavery in the new territories,[1] and the new Utah Territory and New Mexico Territory were allowed, under the principle of popular sovereignty, to decide whether to allow slavery within their borders. In practice, these lands were generally unsuited to plantation agriculture and their settlers were uninterested in slavery. The slave trade (but not slavery altogether) was banned in the District of Columbia. A more stringent Fugitive Slave Law was enacted.

The Compromise became possible after the sudden death of President Zachary Taylor, who, although a slave owner, had favored excluding slavery from the Southwest. Whig leader Henry Clay designed a compromise, which failed to pass in early 1850, due to opposition by both pro-slavery southern Democrats, led by John C. Calhoun, and anti-slavery northern Whigs. Upon Clay's instruction, Douglas then divided Clay's bill into several smaller pieces and narrowly won their passage over the opposition of those with stronger views on both sides.