What was "Bleeding Kansas" primarily about?

"Bleeding Kansas" refers to the period of violent conflict in the Kansas Territory from 1854 to 1859, primarily stemming from the debate over whether Kansas would enter the Union as a free state or a slave state. This turmoil arose after the passage of the Kansas-Nebraska Act, which allowed the residents of Kansas to decide for themselves whether to allow slavery through popular sovereignty. The resulting clashes between pro-slavery settlers and anti-slavery immigrants led to significant violence, including armed confrontations and numerous fatalities, which is why it is often characterized as a violent struggle over the issue of slavery. This historical event was a critical precursor to the larger conflicts that would eventually culminate in the Civil War.