when was bleeding kansas

Bleeding Kansas was a period of violent civil conflict in the Kansas Territory from 1854 to 1859. It arose from the clashes between proslavery and antislavery advocates who were fighting for control of the new territory under the doctrine of popular sovereignty, following the passage of the Kansas- Nebraska Act in 1854. The violence included events like the Sack of Lawrence in May 1856, retaliatory attacks led by John Brown, and ongoing guerrilla warfare between the opposing sides. This turbulent period continued until Kansas was admitted as a free state in January 1861, but the major violence mostly subsided around 1859.