In 1863, U.S. President Abraham Lincoln wrote a scathing letter to his top Union general, who had squandered an opportunity to end the American Civil War. Then Lincoln folded it up and tucked it away in his desk. The letter was never signed and sent—just one example of how Lincoln’s legendary emotional discipline enabled him to rise above mundane arguments and focus on a larger mission. In this episode, Harvard Business School professor and historian Nancy Koehn analyzes Lincoln’s leadership both before and during America’s greatest crisis. You'll learn how emotional self-control can impact your day-to-day leadership as well as your long-term legacy.