>> does this mean that... that we're free? >> that's not my part to say. it is for the president. >> despite his rank, benjamin butler has no strategic military experience, and is considered a disaster on the battlefield. but his tenacity as a lawyer and deft political mind allow him to identify escaped slaves as contrabands of war. butler's controversial decision would eventually inspire thousands of slaves to cross union lines, creating a path for lincoln to entertain the idea of emancipation. >> butler's fort monroe doctrine has an immediate impact on the confederacy. when the union navy invades south carolina's sea islands, plantation owners leave behind 10,000 slaves. these new contrabands begin to grow and harvest cotton and other crops for the union,