 On February 27, 1860, Abraham Lincoln addressed the Young Men s Republican Union in Cooper Union s Great Hall arguing against allowing slavery in the Western territories. This electrifying speech catapulted the little-known Midwesterner into the forefront of Presidential candidates on the Republican ticket and ultimately led to his election as the 16th President of the United States. From the same stage where Lincoln spoke over one hundred years ago, historian Harold Holzer describes the impact of the speech as well as his historical context, followed by actor Sam Waterston delivering the actual address.