Lieber had fought for Prussia in the Napoleonic Wars and had been wounded at the Battle of Waterloo. He later lived and taught for two decades in South Carolina, where he was exposed to the horrors of slavery. Beginning in October 1861, as professor of history and political science on New York at what became Columbia University , Lieber delivered a series of lectures at its new Law School titled "The Laws and Usages of War". He believed the methods used in war needed to align with the goals and that the ends must justify the means.