The Treaty of Guadalupe Hidalgo did not mention the claims of the Republic of Texas; Mexico simply agreed to a border between Mexico and the United States to the south of the “Mexican surrender” claims and the Republic of Texas.  After the end of the Mexican-American War, Texas continued to claim much of the disputed land it had never effectively controlled in what is now eastern New Mexico. New Mexico had long banned slavery, a fact that influenced the debate over its territorial status, but many New Mexico leaders refused to reach Texas, largely because the Texas capital was hundreds of miles away, and because Texas and New Mexico had a history of conflict dating back to the Santa Fe Expedition of 1841.  Outside of Texas, many Southern leaders supported Texas` claims to New Mexico to secure as much territory as possible for the expansion of slavery.  In January 1848, the discovery of gold in California triggered a rapid assault by settlers, more than 80,000 in 1849. Congress had to quickly determine the status of this new region in order to form an organized government. Venerable Kentucky Senator Henry Clay, who had twice presented compromises in times of crisis, presented a complicated and carefully balanced plan. His old Massachusetts rival, Daniel Webster, supported him. Illinois Democratic Senator Stephen A. Douglas, the leading advocate of popular sovereignty, did much of the work to get it through Congress. The general solution adopted by the compromise of 1850 was to transfer a significant part of the territory claimed by the State of Texas to the federal government; officially organize two new territories, the New Mexico Territory and the Utah Territory, which would be explicitly allowed to determine locally whether they would become slaves or free territories to add another free state to the Union (California) in order to take a strict measure to recover slaves who had fled to a free state or territory (the Fugitive Slave Act); and the abolition of the slave trade in the District of Columbia.
A key provision of each of the laws that organized the New Mexico Territory and the Utah Territory, respectively, was that slavery would be decided by local option, called popular sovereignty. It was a significant rejection of the idea behind the failure to ban slavery in an area acquired by Mexico. However, the inclusion of California as a free state meant that the Southerners abandoned their goal of a belt of slave states from coast to coast to coast. Taylor died in July 1850 and was replaced by Vice President Fillmore, who had come privately to support Clay`s proposal.  The various bills were first combined into an “omnibus” certificate. Despite Clay`s best efforts, she failed in a crucial vote on July 31, which was rejected by Southern Democrats and Northern Whigs. He announced the next day in the Senate that he intended to pass all parts of the bill. However, Clay, 73, was physically exhausted when the effects of tuberculosis, which would eventually kill him, wreaked havoc. Clay left the Senate to recover in Newport, Rhode Island, and Senator Stephen A. Douglas took the initiative to try to get Clay`s proposals passed in the Senate.  When the full compromise was not passed, Douglas divided the Omnibus Act into individual bills that allowed members of Congress to vote on any issue or abstain from voting. The untimely death of President Zachary Taylor and the arrival of pro-compromise Vice President Millard Fillmore in the White House contributed to the passage of all bills.
Calhoun died in 1850 and Clay and Webster two years later, making their role in the compromise of 1850 one of their last acts as statesmen. On January 29, 1850, Senator Henry Clay presented a plan that combined the main topics discussed. His legislative package included California`s admission as a free state, texas ceding some of its northern and western land claims in exchange for debt relief, the establishment of the territories of New Mexico and Utah, a ban on the importation of slaves into the District of Columbia for sale, and a stricter fugitive slave law.  Clay initially preferred to vote on each of his proposals separately, but Senator Henry S. Foote of Mississippi convinced him to combine the proposals regarding the inclusion of California and the arrangement of Texas` borders into a single bill.  Clay hoped that this combination of measures would convince members of Congress from the North and the South to support all the laws, even if they opposed certain provisions.  Clay`s proposal received support from some Northern Democrats and Southern Whigs, but did not have the support to pass it, and debate on the bill continued.  Many Northerners believed that slavery would eventually diminish and die if it did not spread. To justify their rejection of the addition of new slave states, they referred to the Washington and Jefferson Declarations and the 1787 ordinance prohibiting the expansion of slavery in the Northwest. Texas, which already allowed slavery, naturally entered the Union as a slave state. But the territories of California, New Mexico, and Utah had no slavery. From the beginning, there were strongly conflicting opinions on whether they should do it.
Both bills were passed by Congress on September 28. It was cancelled in June 1864 after the outbreak of the Civil War, the event that supporters of the 1850 compromise hoped to avoid. The compromise of 1850 consisted of five laws passed in September 1850 that dealt with the issue of slavery and territorial expansion. In 1849, California requested permission to join the Union as a free state, which may have upset the balance between free states and slave states in the U.S. Senate. Senator Henry Clay introduced a series of resolutions on January 29, 1850, to find a compromise and avoid a crisis between North and South. As part of the compromise of 1850, the Fugitive Slave Act was amended and the slave trade was abolished in Washington, D.C. In addition, California joined the Union as a free state and a territorial government was created in Utah. In addition, legislation was passed that settled a border dispute between Texas and New Mexico, which also established a territorial government in New Mexico. The famous Massachusetts orator and senator Daniel Webster, while opposing the expansion of slavery, also saw the 1850 compromise as a way to avoid national discord and disappointed his abolitionist supporters by siding with Clay. A debate about slavery in the territories had erupted during the Mexican-American War, when many Southerners attempted to extend slavery to newly acquired lands, and many Northerners opposed such expansion.
The debate was further complicated by Texas` claim to all former Mexican territories north and east of the Rio Grande, including those it had never effectively controlled. These problems prevented the adoption of organic laws to create organized territorial governments for lands acquired during the Mexican-American War. In early 1850, Clay proposed a legislative package that would resolve the most pressing issues before Congress. Clay`s proposal was challenged by President Zachary Taylor, anti-slavery Whigs like William Seward, and pro-slavery Democrats like John C. Calhoun, and congressional debate over the territories continued. By 1845, it seemed likely that slavery would be limited to areas where it already existed. He had set boundaries by the Missouri Compromise of 1820 and had no way to cross them. The new territories made a further expansion of slavery a real probability. Another issue that would affect the compromise was Texas` debt; there was about $10 million left of debt from its time as an independent nation, and this debt would become a factor in the debates over the territories.  The question of whether the territories would be slave or free came to a boil after Zachary Taylor was elected president in 1848.
In his first annual message to Congress, Taylor advocated California statehood and urged that “exciting issues” that had sparked such concern be left to the courts. He rejected any legislative plan that would solve the problems that so stirred up northerners and south, and prevented Henry Clay from promoting another compromise plan that he hoped would solve the problem for at least a generation, as the Missouri Compromise of 1820 had done. .