Bleeding Kansas
From 1855 to 1858, Kansas Territory experienced extensive violence and some open battles. This period, known as "Bleeding Kansas" or "the Border Wars", directly presaged the American Civil War. The major incidents of Bleeding Kansas include the Wakarusa War, the Sacking of Lawrence, the Pottawatomie massacre, the Battle of Black Jack, the Battle of Osawatomie, and the Marais des Cygnes massacre.