Bleeding Kansas refers to which historical event?

Bleeding Kansas refers to a series of violent confrontations in the territory of Kansas during the mid-1850s, primarily over the contentious issue of slavery and whether Kansas would enter the Union as a free or slave state. This bloodshed was a direct result of the Kansas-Nebraska Act of 1854, which allowed the residents of those territories to decide through popular sovereignty whether they would allow slavery. The act led to significant conflict between pro-slavery and anti-slavery settlers, resulting in numerous violent clashes, deaths, and further escalation of sectional tensions that would eventually contribute to the Civil War. The period symbolized the deep divisions in the United States regarding the institution of slavery and foreshadowed the broader conflicts to come.