He proposed a bill that divided the land west of Missouri into two territories, Kansas and Nebraska.
Law passed in 1854 allowing the people of these two territories to decide for themselfs whether to allow slavery.
The Kansas-Nebraska Act of May 30th 1854, created the territories of Kansas and Nebraska, opened new lands, and allowed settlers in those territories to determine if they would allow slavery within their boundaries.
The Republicans
Between 1854 and 1861, the area of territory open to slavery expanded significantly due to the Kansas-Nebraska Act of 1854, which allowed new territories to decide on the legality of slavery through popular sovereignty. This led to violent conflicts known as "Bleeding Kansas" as pro-slavery and anti-slavery settlers rushed into the territories. Additionally, the Dred Scott decision in 1857 further entrenched the status of slavery, declaring that Congress had no power to regulate slavery in the territories. By 1861, the political landscape was increasingly polarized, with more territories and states aligning with the institution of slavery.
In 1854, the territories that were non-slave-holding included the free states of the North and territories established under the Missouri Compromise, such as the Oregon Territory. It is important to note that the Kansas-Nebraska Act of 1854 introduced the concept of popular sovereignty, allowing settlers in those territories to decide on the legality of slavery, leading to significant conflict. As a result, the status of slavery in these areas was contentious and evolving rather than strictly non-slave-holding.
Northern abolitionists and free soilers would have been concerned about the potential spread of slavery into new territories with the passage of the Kansas-Nebraska Act in 1854. This act allowed for popular sovereignty in these territories, which could have led to the expansion of slavery into areas where it had previously been prohibited.
The main purpose of the Kansas-Nebraska Act of 1854 was to give voters in each of the two territories the right to vote on whether slavery would be allowed before the territories applied for statehood.
Texas & New Mexico.
The Kansas-Nebraska Act (1854)
New Mexico was lost by Mexico during the Mexican-American War (1846-1848). Later, some territories on southern New Mexico were sold by Mexico to the US at the Gadsden Purchase (1854).
Nebraska Territory and Kansas Territory or you could just look in a textbook