What was the "Kansas-Nebraska Act"?

The Kansas-Nebraska Act was significant because it established the territories of Kansas and Nebraska while introducing the concept of popular sovereignty, which allowed the settlers in those territories to determine whether they would permit slavery or not. This act, passed in 1854, was a pivotal moment in U.S. history as it effectively repealed the Missouri Compromise, which had previously prohibited slavery in that northern region.

The act was intended to facilitate the construction of a transcontinental railroad and foster westward expansion. However, it led to intense political conflict and violence, most notably in "Bleeding Kansas," as pro-slavery and anti-slavery settlers rushed into the territories to influence the outcome of the vote on slavery. The impact of the Kansas-Nebraska Act not only heightened tensions between the North and South but also contributed to the rising sectional conflict that eventually led to the Civil War.