It passed the Senate July 27, 1848, but it was tabled in the United States House of Representatives by a coalition of Southern Whigs led by future Confederate Vice President Alexander H. Stephens.
[2] In the 19th century, manifest destiny was a widely held belief in the United States that its settlers were destined to expand westward across North America.
In the Treaty of Guadalupe Hidalgo in 1848, Mexico ceded parts of the modern day Southwest United States to the U.S. Mexican cession led to debate over slavery.
When established, the territory encompassed an area that included the current states of Oregon, Washington, and Idaho, as well as parts of Wyoming and Montana.
Charles G. Atherton and Samuel S. Phelps were the only New England Democratic and Whig Senators, respectively, to vote in favor of the Clayton Compromise bill.