The correct answer is Northerners and Southerners were not ready to resort to violence to abolish slavery.
At the time of the raid, 1859, Americans in the North and South were constantly trying to find peaceful way to resolve their conflicts regarding the expansion of the institution of slavery. Congress had made several deals that would avoid violence. This included the Missouri Compromise, the Compromise of 1850, and the Kansas-Nebraska Act.
All of these shows Americans dedication to avoid war. However, John Brown felt that the only way to get rid of the evil institution of slavery was through violence. This is why his raid on harper's ferry was not successful, as only a few hundred people supported his radical idea.