The authors of a new book on how lessons from Gettysburg remain relevant for today’s leaders will speak June 29 at a webinar hosted by the Association of the U.S. Army.

Battle Tested! Gettysburg Leadership Lessons for 21st Century Leaders was written by retired Col. Tom Vossler and retired Col. Jeff McCausland. The discussion with them, part of AUSA’s Thought Leaders series, begins at 2 p.m. Eastern. It is free, but registration is required here.

The Battle of Gettysburg, in July 1863, was a turning point in the Civil War, with the Union victory that ended Gen. Robert Lee’s second and most ambitious invasion of the North. It was the Civil War’s bloodiest battle, according to the National Park Service, and the inspiration for President Abraham Lincoln’s Gettysburg Address.

At Gettysburg, Union and Confederate commanders faced a series of critical leadership challenges under the enormous stress of combat. The fate of the nation hung in the balance. These leaders each responded in different ways, but the concepts and principles they applied during those traumatic three days contain critical lessons for today’s leaders that are both useful and applicable, according to a description of the book.

During the webinar, McCausland and Vossler will use examples from the battle to show leaders how to make the right decisions and guide their people while under pressure.

Vossler, who retired from the Army in 1998, commanded an infantry platoon in Vietnam and a battalion task force in Germany before the fall of the Berlin Wall. He has taught military history, strategy and leadership at the Army War College and is a former director of the Army Military History Institute at Carlisle Barracks, Pennsylvania.

McCausland, who retired from the Army in 2002, is a former dean of academics at the Army War College and founder and CEO of Diamond6 Leadership and Strategy. He has a master’s and a doctorate from the Fletcher School of Law and Diplomacy at Tufts University and is a visiting professor of international security at Dickinson College.