At this time in history, there was much contention about slavery and whether it was legal and/or constitutional. With new territories that were acquired there had to be a decision made as to whether they would be free or slave states. With many of the Southern states threatening to break away from the Union, Congress was pressured to reach a compromise to please all states. Congress temporarily solved the slavery issue as they continued to expand and acquire territory with the Oregon Treaty, the Compromise of 1850, and the Fugitive Slave Act.
The Oregon Treaty of 1846 came with the US acquiring the Oregon territory from Britain. The US received land south of the 49th parallel latitude line and Britain gained land north of the parallel along with Vancouver Island. Slavery was to be illegal in the US Oregon territory.
The Compromise of 1850 set forth to please the Free States by: California being admitted to the Union as a free state, Texas loses boundary area, and slave trading being outlawed in the Capitol of Washington DC.
Slave states were pleased with the following: no slavery restrictions in Utah or New Mexico, Texas received $10 million in exchange for land, slave holding permitted in Washington, DC, and the Fugitive Slave Act of 1850 being passed.
The Fugitive Slave Act of 1850 contended that runaway slaves were allowed to be captured and returned to their owner.