This is Brian R. McEnany speaking at the US Army Heritage and Education Center on the West Point Class of 1862 in the Civil War. There’s some pretty good information here.
The video’s description reads, ” ‘For Brotherhood and Duty: The Civil War History of the West Point Class of 1862’ by LTC (Ret.) Brian R. McEnany
“ ‘Joined in Common Cause,’ was the motto adopted by the 28 cadets remaining enrolled at the United States Military Academy at West Point the spring of 1862. Half of their brothers in arms, among the secession of their home states from the Union they swore to protect and the roiling turmoil of war, had resigned and taken their new-found military skills south. Yet these students of military science remained to march in the long gray line to serve their country in the coming years of bloodshed as the leaders down on the front, in the blood and guts of their Soldiers, commanding charges and bringing unions back to the nation.
“Brian R. McEnany spent years in archives across the country writing his book, For Brotherhood and Duty: The Civil War History of the West Point Class of 1862. In this lecture-version of his research, he will focus on sixteen young cadets, as they struggle through their classes while watching the country fall to violent pieces around them. Following these twelve Federal and four Confederate officers onto the battlefield, he uses first person accounts, as well as numerous other primary sources, to give life to their personal alliances, demons, and struggles. Each account not only sheds light on the junior leadership during such battles as Antietam, Fredericksburg, and Gettysburg, but also reflects on the senior leadership, national strategy, and the soul of the armies contesting the rights of the Federal government versus the states.”